ISUZU 4HK1 Service Manual

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Page 1

WORKSHOP MANUAL

727 (N SERIES)

ENGINE CONTROL SYSTEM

(4HK1 ENGINE)

SECTION 1A

International Service & Parts

Tokyo, Japan

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N O T I C E

Before using this Workshop Manual to assist you in performing vehicle service and maintenance operations, it is recommended that you carefully read and thoroughly understand the information contained in Section - 0A under the headings “GENERAL REPAIR INSTRUCTIONS” and “HOW TO USE THIS MANUAL”.

All material contained in this Manual is based on the latest product information available at the time of publication. All rights are reserved to make changes at any time without prior notice.

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Engine Control System 1A-1

ENGINE

Engine Control System

CONTENTS

Engine Control System . . . . . . . . . . . . . . . . . . . . 1A-2

Precautions on Service . . . . . . . . . . . . . . . . . . . 1A-2

Function and Operation. . . . . . . . . . . . . . . . . . . 1A-4

Component Layout . . . . . . . . . . . . . . . . . . . . . 1A-20

Circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . 1A-25

Strategy-Based Diagnostics . . . . . . . . . . . . . . 1A-31

Functional Check List . . . . . . . . . . . . . . . . . . . 1A-37

Hearing Diagnostic . . . . . . . . . . . . . . . . . . . . . 1A-37

On-Board Diagnostic (OBD) System Check . . 1A-39

Inactive CHECK ENGINE Lamp (MIL) . . . . . . 1A-41

CHECK ENGINE Lamp (MIL) Remains Active 1A-44

Engine Cranks But Will Not Run. . . . . . . . . . . 1A-46

Diagnosis with Tech 2 Scan Tool. . . . . . . . . . . 1A-48

Diagnostic Chart . . . . . . . . . . . . . . . . . . . . . . . 1A-67

DTC11 - No Signal CKP Sensor . . . . . . . . . . . 1A-73

DTC13 - TCV Fault . . . . . . . . . . . . . . . . . . . . . 1A-75

DTC14 - Pump ROM Fault . . . . . . . . . . . . . . . 1A-78

DTC15 - Pump Cam Sensor (NE Sensor)

Short Break Fault . . . . . . . . . . . . . . . . . . . . . . 1A-80

DTC16 - No Signal from Pump Cam Sensor

(NE Sensor) . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-82

DTC21 - ECT Sensor Fault. . . . . . . . . . . . . . . 1A-84

DCT23 - IAT Sensor Fault. . . . . . . . . . . . . . . . 1A-88

DTC24 - AP Sensor Output Fault . . . . . . . . . . 1A-91

DTC25 - VS Sensor Circuit Fault . . . . . . . . . . 1A-95

DTC31 - Idle Up Volume Fault . . . . . . . . . . . . 1A-98

DTC32 - MAP Sensor Fault . . . . . . . . . . . . . 1A-101

DTC34 - Exhaust Brake Open Wiring Fault . 1A-104

DTC35 - Neutral Switch Signal Fault . . . . . . 1A-106

DTC36 - Clutch Switch Signal Fault

(M/T Vehicle only) . . . . . . . . . . . . . . . . . . . . . 1A-108

DTC41 - FT Sensor Cir cuit High Voltage . . . 1A-110 DTC51 - Atmospheric Pressure Sensor Fault 1A-113

DTC52 - ECM Internal Fault . . . . . . . . . . . . . 1A-114

DTC53 - Engine Driver Unit Fault . . . . . . . . . 1A-116

DTC55 - Pump Unmatched

(Difference from ECM Specifications). . . . . . 1A-118

DTC65 - Idle Position Switch Fault . . . . . . . . 1A-120

Symptom Diagnosis Chart . . . . . . . . . . . . . . 1A-122

Hard Starting. . . . . . . . . . . . . . . . . . . . . . . . . 1A-123

Vehicle Speed Variation . . . . . . . . . . . . . . . . 1A-127

Lack Power or Faulty Response . . . . . . . . . . 1A-130

Unstable Idling . . . . . . . . . . . . . . . . . . . . . . . 1A-134

Engine Not Stall . . . . . . . . . . . . . . . . . . . . . . 1A-137

Starter Motor does Not Run . . . . . . . . . . . . . 1A-139

Quick On Start (QOS) System does Not

Operate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-142

Excessive Black Smoke in Exhaust Gas. . . . 1A-144

Excessive White Smoke in Exhaust Gas . . . 1A-147

Noisy Engine. . . . . . . . . . . . . . . . . . . . . . . . . 1A-149

Nasty Smell. . . . . . . . . . . . . . . . . . . . . . . . . . 1A-152

Poor Fuel Economy. . . . . . . . . . . . . . . . . . . . 1A-155

Excessive Engine Oil Consumption . . . . . . . 1A-159

Large Engine Vibration . . . . . . . . . . . . . . . . . 1A-161

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-164

Wiring Harness Repair: Shielded Cable. . . . . . 1A-165

Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-165

Installation Procedure . . . . . . . . . . . . . . . . . . 1A-165

Twisted Leads . . . . . . . . . . . . . . . . . . . . . . . . . 1A-166

Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-166

Installation Procedure . . . . . . . . . . . . . . . . . . 1A-166

Weather-Pack Connector. . . . . . . . . . . . . . . . . 1A-168

Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-168

Installation Procedure . . . . . . . . . . . . . . . . . . 1A-168

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-169

Com-Pack III. . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-170

General Information . . . . . . . . . . . . . . . . . . . 1A-170

Metri-Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-171

Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-171

Installation Procedure . . . . . . . . . . . . . . . . . . 1A-171

Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-171

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1A-2 Engine Control System

Engine Control System

Precautions on Servic e

Circuit Test Tools

Unless otherwise specified in diagnostic procedures, do not use Test Light to diagnose the powertrain electrical system. When diagnostic procedures need probe connector, use Connector Test Adapter Kit 58840-0385-0.

On-Market Electrical Equipment and Vacuum Devices

On-market electrical equipment and vacuum devices refer to those components that will be installed to vehicles after shipme nt from manufacturing plants. Be careful that installation of these components is not considered during the process of vehicle design.

CAUTION: Do not install on-market vacuum devices to vehicles.

CAUTION: Connect on-market electrical equipment, as well as its power supplies and grounds, to the circuits isolated from the electronic control system.

The on-market electrical equipment, even when installed to vehicles in normal manner, may bring functional troubles to the electronic control system. Affected devices include those not connected to the vehicle electrical equipment system, for example, mobile phones or radios. Therefore, when you intend to diagnose the powertrain, check such the on-market electrical equipment has not been installed to the vehicle and, if installed, remove it. If faults still occur even after removal of on-market electric al equipment, diagnose the vehicle according to normal procedures.

List of Abbreviations

Damage by Electrostatic Discharge

Electronic components used in the electronic control system are designed to wor k at very low volt ages and, for this reason, they are susceptible to damage by electrostatic discharge and some types of electronic components may be damaged even by the static electricity of less than 100 V that is usua lly not sens ed by persons. Persons’ sensitivity level is 4,000 V. Persons are electrostatically charged in various ways and the most typical el ectrification sources are fric tion and induction. Shown below are examples.

• Electrification by friction occurs when a person slides on the seat in the vehicle.

• Electrification by i nduction occurs when a person with insulating shoes is standing near a highly electrifiable substance and touches a ground momentarily. Electric charges with the same polarity flow out and resultantly the person is charged at high opposite polarity. Since static electric charges cause damages, it is important when you handle or test electronic components.

CAUTION: To prevent damages by electrostatic discharge, follow the guidelines shown below.

• Do not touch ECM connector pins as well as electronic components soldered to the ECM circuit board.

• Do not unpack each replacement component until preparations are completed for the component.

• Before taking out a component from the package, connect the package to the normal grounding line of the vehicle.

• When you intend to slide on the seat, change the posture from standing to sitting, or wa lk by a certain distance to handle a component, touch an appropriate grounding material.

Abbreviation Original form Meaning in this manual A/C Air Conditioner Air conditioning units (cooler, heater, etc.) AP Accelerate Position Depressing stroke of accelerator pedal CKP Crankshaft Position Rotating reference signal of crankshaft CMP Camshaft Position Rotating reference signal of pump camshaft DLC Data Link Connector DLC connector (Tech 2 communication connector) DTC Diagnosis Trouble Code DTC code DVM Digital Volt Meter Special service tool (part No. 5-8840-0366-0) ECT Engine Coolant Temperature Coolant temperature ECM Engine Control Modulle Engine control computer EDU Engine Driver Unit Fuel pump spill valve drive unit

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Engine Control System 1A-3

Abbreviation Original form Meaning in this manual EGR Exhaust Gas Recirculation Exhaust gas recirculation ISM Intake Step Motor Intake throttle valve drive motor ITP Intake Throttle Position Intake throttle valve opening MIL Malfunction Indicator Lamp CHECK ENGINE Lamp SPV Spill Control Valve Valve for high pressure circuit in the fuel pump SW Switch TCV Timing Control Valve Injection timing control valve in the fuel pump Key SW Key switch Starter switch

Wire Color

All wiring harnes ses are i den tifi ed us in g c ol ored jacket. The wiring harness used for the main circuit in an electrical system is i den tif ied wi th sin gl e c olor whi le the wiring harness us ed for th e sub -circui t is id entifi ed with color stripe. The following rule is used in each wiring diagram to indicate size and color of a wiring harness.

eg. : 0.5 GRN / RED

Legend

1. Red (stripe color)

2. Green (base color)

3. Harness size (0.5 mm

Symbol Color Symbol Color

B Black BR Brown

W White LG Light green

RRedGRGray

LNW21ASH000101-X

)

G Green P P ink Y Yellow LB Light blue L Blue V Violet O Orange

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1A-4 Engine Control System Function and Operation

Electronic Control System

The electronic control system processes the data, which has been collected with various types of sensors, by means of the control program installed to ECM (engine control module) to totally control engine parameters such as fuel injection amount, injection timing, engine startup, altitude compensation, and EGR.

Sensor Actuator Control

Engine Rotating Speed

(Built-in Injection Pump)

Crankshaft Position

Accelerator Position

Coolant Temperature

Fuel Temperature

(Built-in Injection Pump)

Intake Air Pressure

Vehicle Speed

ECM

Engine Driver Unit

Injection Pump

Spill Control Valve

Timing Control Valve

EGR Valve Engine Control Module

Intake Throttle Valve

Exhaust Magnetic Valve

Fuel Injection Volume

Control

Fuel Injection Timing

Control

Idle Rotating Speed

Control

Starting Control

Altitude Control

EGR Control

Intake Air Throttle

Control

Exhaust Brake Control

Idle Up Volume

Intake Air Temperature

Atmospheric Pressure

(Built-in ECU)

ECM ECM Description

The ECM is mounted in the glove box. The ECM monitors va ri ou s da ta se n t fr om d iv e rsi fi e d se ns or s a n d controls systems in the powertrain. The ECM diagnoses these s ystems to detect faults with resp ect to system operations and inform the driver of faulty condition via the CHECK ENGINE Lamp (MIL) and stores DTCs (diagnosti c trouble codes ). DTC identifi es the trouble generation area to aid repairs by service operators.

Glow Plug

Glow Lamp

CHECK ENGINE Lamp

Swirl Change-Over Valve

Warm-Up System

Control

Starting Aid Control

Self Diagnosis

Intake Air Swirl Control

LNW21ALF000301-X

Function of ECM

ECM supplies 5 V and 12 V voltages to various sensors and switches. Since powers are supplied via high resistances in ECM , Test Light, eve n when connected to the circuit, will not be lit. In a spe cial case, a normal voltmeter does not indicate correct values since the resistance of the instru ment is to o low. To get accu rate readings, you need a digital voltmeter whose input impedance is at least 10 M Ω. The special tool 5-88400366-0 is a pro per ch oice fo r this m easurement. In t he ECM, the output circuit is con trolled by regulating the

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Engine Control System 1A-5

grounding system or power circuit via transistor or either of the devices listed below.

• Output driver module (ODM)

• Quad drive module (QDM)

ECM and Components

The ECM is designed to offer excellent drivability and fuel economy while achieving exhaust gas emission control requirements. The ECM monitors engine and vehicle functions via various electronic sensors such as CKP (crank position) and VS (vehicle speed) sensors.

Voltages from ECM

The ECM supplies reference voltages to various switches and sensors. Resistances of the ECM are very high and this allows the ECM to supply voltages to these devices, and voltag es actually applied to circuits are low and even connecting Test Light to individual circuits may fail turn-on. Since the voltmeter normal ly used in service factories has low input impedance, correct readings may not be obtained . To get a ccurate readings, a digi tal voltm eter whose i nput impeda nce is 10 MΩ (for example, 5-8840-0366-0) should be used. Input/output devices of the ECM include analog-todigital converter, signal buffer, counter, and special driver. By using electronic switches, th e ECM controls most system components and turning off a switch closes the ground circuit. These switches are divided into four-switch or seven-s wit ch groups, and the former group is called quad dr i ver m odu le ( QD M) an d c ontro ls up to four output pins respectively while the latter group is called output driver module (ODM) and controls up to seven outputs respectively . Note that all the outputs are necessarily not used in the control.

Electrically Erasable Programmable ROM (EEPROM)

EEPROM is a permanent memory chip and soldered to the board in the ECM. EEPROM stores program and calibration data, both of which are necessary for the ECM to control the powertrain. Different from conventional ROMs, EEPROM cannot be replaced with new component. If EEP ROM fails, the complete ECM assembly must be replaced with new one.

engine fault to the user. In a service factory, 4 pins and 6 pins of DLC (data link connector) can be short to check the DTC while the CHECK ENGINE Lamp (MIL) is flashing.

LNW21ASH000201

87654321

161514131211109

LNW21ASH000301

Precautions on ECM Service

The ECM is designed to withstand ordinary currents used in operations of a vehicle. Be careful that the circuits must not be overloaded. To test the ECM to check open wiring or short, ECM circuits must be connected to the ground or voltages must not be applied to the ECM. To test ECM circuits, the digital voltmeter 5-8840-0366-0 should always be used.

CHECK ENGINE Lamp (MIL)

Used as a means of communication between ECM and user usually in the user mode, by light on and off. If this lamp illuminates during operation, it warns some

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1A-6 Engine Control System

Electronically Controlled Distributor Injection Pump

Legend

1. Spill control valve

2. Pump cam position sensor (engine speed sensor)

3. Inlet pipe

4. Fuel temperature sensor

5. Accumulator

6. Bearing cover

An electronically contr olled distribu tor inj ectio n pump is employed to meet the requirements of the long-term exhaust gas control without impairing the fuel efficiency and output. These features allow finer particles of injected fuel, and optimum injection timing and injection amount while the vehicle is traveling, which was impossible with the former injection pump.

LNW21ALF000101

7. Timer

8. Timing control valve

9. Delivery valve holder

10. Compensation ROM 11 . Overflow pipe

12. Overflow valve

Fuel Dehumidifying Agent

Sliding parts in the in jec ti on p ump are lubricated by t he fuel (light oil) as in the ex isting d istr ibutor ty pe in jecti on pump. If dehumidifying agent is mixed in the fuel, it may exert adverse influence on the sliding parts. Particularly, dehumidifying agent of alcohol type is characterized by introducing moisture into water, causing rust generation. It should be explained to customers not to use fu el dehumid ifying ag ent or other fuel additives.

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Structure and Operation

1. Higher pressure of injection fuel An inner cam with a cam ring and radial plunger are used to in crease the pressure o f the injection fuel. The cam ring is supported on th e pump body side and provided with projections (cams) on the internal periphery. Four plungers are provided at an interval of 90°, incorporated in the rotor i ntegrated with the drive shaft, and in contact with the internal periphery of the cam ring in the radial direction through the roller. When the drive shaft rotates, the plunger moves on the cam ri ng int er nal s ur fac e throug h the rolling of the roller, pushed out in the shaft center direction with th e inner cam and compresses the fuel. Four plungers operate simultaneously. This enables higher pr essure (75 ~ 130 M Pa) and high rigidity is o btained since the lo ad bec om es rel ati ve load in the radial direction. Plunger diameter is ø7.5mm and the cam lift is

2.5mm.

Engine Control System 1A-7

3. Fuel injection amount control Fuel injection amount is adjusted by opening or closing the fuel high pressur e circuit with the high response SPV (spill control valve). EDU (engine driver unit; a high voltage driver) is employed to drive the SPV at a high speed . EDU can drive the SPV o f high fuel pressure at a high speed by the high voltage and high speed energizing system.

4. Pump ROM In order to compensate the variation of correlation between the fuel pump and engine, variation of the injection amount in herent to the injection pump is corrected.

5. Air bleeding of injection pump a. Pumping until the pump is hard to operate. b. Start the engine. If not started, repeat

pumping.

c. After the engine is started, keep the engine

speed at 1000 to 1500rpm for about 10

seconds. d. Stop the engine. e. Check for fuel leakage.

LNW21ASH000401

Legend

1. Cam ring

2. Rotor

3. Timer piston

4. Roller

5. Plunger

2. Injection timing control Injection timi ng is ad ju sted by shifting the cam ring phase with the fue l p ress ure app li ed t o th e back of the timer piston. The fuel pressu re applied to the timer piston is controlled with the ECM (engine control module) through the timing control valve.

Legend

1. Priming pump

2. Plug

3. Sensor

4. Cartridge

LNW21ASH000501

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1A-8 Engine Control System

EGR (Exhaust Gas Recirculation) Valve

In order to decrease NOx (nitrogen oxide) in the exhaust gas, an EGR system is employed. The EGR valve is vacuum control type.

LNW21ASF000101

Legend

1. Diaphragm

2. Valve

LNW21ASF000201

3. Exhaust gas

4. Vacuum

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Injection Nozzle

Legend

1. Edge filter

Engine Control System 1A-9

LNW21ASF000301

A two-step valve opening pressure nozzle is used as the injection no zzle. Spray pa rticle size i s reduced by reducing the injection hole diameter. To prevent clogging of the nozzle injection hole, an edge filter is provided at the nozzle holder inlet.

Reference: If the injection nozzle hole is clogged, ECM corrects the cylinder inside condition. The cylinder correction amount in the Tech 2 data list is helpful to know the injection nozzle condition.

Item Engine 4HK1

Valve opening pressure MPa(kg/cm

1st valve op ening pressure

2nd valve

)

opening pressure

No. of injection holes - Injection

18.0 {185}

(Nominal value)

22.0 {225}

(Nominal value)

5 -ø0.25

hole diameter (mm)

Fuel Filter with Sedimentor

In order to secure the lubrication efficiency in the injection pump, a fuel filter with sedimentor to remove moisture in the fuel is provided. This filter is pro vided with a priming pump to bleed th e air from the injection pump.

LNW21ASH000601

Legend

1. Priming pump

2. Fuel filter & sedimentor

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1A-10 Engine Control System

Pump CMP (Cam Position) Sensor (Engine Rotation Sensor ) = NE Sensor

The pump CMP sensor is positioned on the outer surface of the cam ring of the pump chamber. The pulser installed to the injection pump drive shaft interrupts the magnetic flux generated by the permanent magnet and iron core of the sensor according to the shaft rotation to generate AC wave signal to the coil. This is transmitted to ECM (engine control module) and converted to square wave signal . engine speed and cam position are calculated by this signal.

• Calculation of engine speed: No. of pulses per hour is counted.

• Calculation of cam position: When the cam ring slides, timing of sign al read from the pulse of the sensor installed to the cam ring varies. ECM calculates the time difference be tween this signal and signal of the crank position sensor and calculates the cam position.

CKP (Crank Position) Sensor

CKP sensor to detec t the crank position is installed to the flywheel housin g. The sensor detec ts the rotating angle of the crankshaft in non-contact condition with the pointer installed to the flywheel and sends pulse signal to ECM. ECM calc ulates the injection timin g at the pump cam position based on this pulse signal.

Legend

1. Iron core

2. Magnetic flux

3. Permanent magnet

4. Coil

5. Pulser

LNW21AMH000101

Legend

LNW21ASH000701

1. (–) Pin

2. (+) Pin

Page 13

Accelerator Position Sensor

The accelerator control is accelerator position sensor type. This sensor is a potentiometer (variable resistance) installed to the accelerator pedal. Reference voltage i s constantly applied to the sens or from ECM (engine control modul e) and the accelerat or pedal stepping ang le is detected from varying voltage . An accelerator switch (idle position switch) is also installed to the accelerator pedal. The accelerator switch is turned ON when the accelerator pedal is released and OFF when the accelerator pedal is stepped on.

Engine Control System 1A-11

(V)

(WOT)

Output Voltage

(Idle)

10 20 30

Stroke (on Pedal)

Legend

1. Accelerator position sensor 2. Accelerator switch operating point

Engine Coolant Temperature Sensor (Coolant Temperature Sensor / ECT)

The engine coolant tempe ratur e s ensor se rves for both the ECM and thermo m eter unit. The engine coolant temperature sensor is of the thermistor type that the electric resistance reduces with the increase of the temperature. It is installed on the left front of the cylinder head.

40 50 (mm)

LNW21AMF000701-X

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1A-12 Engine Control System

Intake Air Temperature Sensor

Intake air temperatur e sensor is installed to the i ntake duct. Thermistor is used for the temperature detec tor as in the thermo sensor to convert the changes of temperature to changes of resistance values and transmits to ECM.

ACB

Legend

1. Thermistor for ECM

2. Thermistor for thermo meter

[Thermistor Characteristics]

7.0

5.0

3.0

2.0

1.0

0.7

Resistance Value (k )

0.5

0.3

0.2

0.1

-20 1200 10020 8040 60

Engine Coolant Temperature ( C)

LNW21ASH000801

LNW21ASH001001

Atmospheric Pressure Sensor

The atmospheric pressure sensor is incorporated in ECM.

MAP (Intake Air Pressure) Sensor

The MAP sensor is installed to the cylinder head cover. The MAP sensor is composed of piezo type semiconductor pressure element. Reference voltage is constantly applied to the MAP sensor from ECM and manifold pressure is detected by the changes of voltage. When the manifol d pressure is low ( at idling), low voltage signal is sent to ECM and when the pressure is high (at ful l throttle), high voltage signa l is

LNW21ASH000901-X

transmitted to ECM.

Fuel Temperature Sensor

Fuel temperature sensor is installed in the pump chamber full of fuel. Thermistor is used for the temperature detector as in the thermo sensor and convert the changes of temperature to changes of resistance and values transmits to ECM.

Vehicle Speed Sensor

The vehicle speed sensor is used commonly with the speedometer. ECM receives signal from the speedometer. By one turn of the sp eedome ter driven gear, 25 pulses are generated indicating 60 km/h at 637rpm.

LNW21ASH001101

Page 15

MAP (Intake Air Pressure) Sensor

Engine Control System 1A-13

[MAP Sensor Characteristics]

Output Voltage (V)

Legend

1. Pressure at idling (low pressure)

2. Pressure at ratin g p oint (a bsolut e pre ssure (high pressure))

3. Power pin

EDU (Engine Driver Unit)

EDU enables SPV high speed drive at high fuel pressure by the high voltage and high speed energizing system. Maximum charging voltage is about 150V.

Absolute Pressure

4. Output pin

5. Ground pin

6. Vacuum hose connected pipe

Legend

1. EDU

2. Left side cover

LNW21AMF000801-X

LNW21ASH001201

Connecting Diagram

Battery

ECM

High Voltage

Generating

Circuit

Control

Circuit

SPV+

SPV

Ground

LNW21ASH001601-X

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1A-14 Engine Control System

SPV (Spill Control Valve)

Fuel injection amount is controlled with the highresponse SPV by opening and closing the fuel high pressure circuit. SPV is incorporated in the injection pump.

Legend

1. SPV drive signal

2. EDU

3. ECM

4. High pressure fuel

LNW21AMF000901

5. Valve

6. High pressure fuel passage

7. SPV

8. B-B section

Page 17

TCV (Timing Control Valve)

TCV using a solenoid valve is installed to the oil pressure timer. Duty (energizing rate) controlled current with ECM increases or decreases the valve opening time to control the oil pressure in the high pressure chamber si de. The timer piston is mo ved by the balance with the timer s pring. By sliding the cam ring connected movably with the timer piston in the rotating direction, the injection timing is controlled.

Engine Control System 1A-15

Legend

1. Cam ring

2. Low pressure chamber

3. Timer spring

4. TCV

Electronic Control Distributor Pump System System Overview

The accelerator control uses an accelerator position sensor. The accelerator sensor of the potentio meter (variable resistanc e) type is installed to the ac celerator pedal. Reference volta ge is constantly applied to the sensor from the ECM (engin e con tr ol module) to det ec t the accelerator ped al stepping angle from changes of voltage. An idle posi tion switc h (acceler ator switch ) is also installed to the accelerator pedal. The idle position switch (accelerator switch ) is turned ON when the accelerator pedal is released and OFF when the accelerator is stepped on. ECM detects the accelerator pedal stepping angle as AP (accelerator position) signal and after calculating, transmits SPV (spill controller valve) drive signal to EDU (engine driver unit). EDU enables high spee d drive of SPV which controls fuel injection amount. The fuel injectio n amount is contr olled by opening and closing the fuel high pressure circuit with the high response SPV. SPV is incorporated in the injection pump. The spill control valve and timing control valve are

LNW21ASF000401

5. High pressure chamber

6. Timer piston

7. From ECM

electronically controlled with ECM (engine control module).

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1A-16 Engine Control System

Legend

1. Timer piston

2. Plunger

3. Cam ring

4. Pump cam position signal (engine speed signal)

5. Spill control valve

6. Spill control valve drive signal

7. Engine driver unit

8. Engine control module

9. Accelerator pedal opening signal

10. Accelerator position signal

Fuel Injection Amount Control

The electromagnetic spi ll valve is o pened by the signal from ECM (engine contr ol m odul e) , pres su r e in the fuel forced feed unit (rotor unit) is decreased and injection is completed. Injection amount is controlled at this timing.

LNW21ALF003101

11. Crankshaft position signal

12. Engine

13. High pressure fuel passage

14. Injection timing control si gna l

15. Timing control valve

16. Timer piston

17. Pump cam position sensor (engine speed sensor)

18. A-A section

19. B-B section

Page 19

Operation

ECM calculates the bas ic injection amount op timum to the engine operating conditions and the maximum injection amount at that engine condition, compares and selects lower injection amount. By adding the phase compensated with the compensation ROM to that injection amount, the final injection amount is determined.

Engine Control System 1A-17

At the time of start, the optimum fuel injection amount is determined by the starter signal and coolant temperature. (Injec tion amount increases more wh en the coolant temperature is lower.)

Accelerator Position

Sensor

Basic Injection Amount

Select Lower Injection

Amount Side

Compen-

sation

Injection Amount

Determine

EDU

Engine Speed Sensor

Basic Max. Injection

Amount

Compen-

sation

Max. Injection Amount

Intake Air Pressure

Sensor

Increase When Higher

Intake Air Temperature

Sensor

Varying Depending on

Conditions

Fuel Temperature Sensor

Increases When Lower

Coolant Temperature

Sensor

Increases When Lower

Fuel Temperature Sensor

Compensates to Increasing

Side When Higher

Compensation ROM

Compensation Value

of Each Pump

Electromagnetic Spill Valve

LNW21AMF001001-X

1. Basic injection amount Determined by accelerator opening and engine speed.

2. Max. injection amount Maximum injection amount is determined by adding compensati on by signals of sen sors to the basic maximum injection amount (amount which can be theoretic ally in jec ted ) dete rm in ed ba se d on the engine speed.

a. Intake air pressure compensation

When the intake air pressure is high, the air amount is increased and the injection amount is increased.

b. Intake air temperature compensation

Injection amount is increased or decreased depending on the difference of density based on the intake air temperature.

c. Fuel temperature compensation

When the fuel temperature decreases, the injection amount is increased.

d. Coolant temperature compensation

When the coolant temperature is lower, the injection amount is increased to secure the operability immediately after the cold start.

3. Injection amount compensation Since the actual injection amount decreases in comparison with the des ignated value of injection amount when the fuel temperature is higher, designated injection amount value is increased.

Fuel Injection Timing Control

• Timing control valve is duty-controlled according to a signal from ECM (engine control module) to control the fuel injection start timing.

• Using the crankshaft angle feed back system, highly precise control is effected.

Page 20

1A-18 Engine Control System

Operation

ECM calculates the o ptimum target injection ti ming for the engine condition, adding the compensation by signals from sensors based on the basic target injection timing. At the time of start, the injection timing is determined by the starter signal, coolant temperature and engine speed (at the higher engine spee d, the injecti on timing angle advances.) Crank angle feed back system is emp loyed to c alculate the actual inject ion timing and feed back the res ult at the target injection timing.

Accelerator Position

Sensor

Basic Target Injection

Timing

Compen-

sation

Target Injection Timing

Comparison with Target

Injection Timing and

Actual Injection Timing

Calculation of Duty Ratio

Actual Injection Timing

Timing Control Valve

Speed Sensor

Compen-

sation

Crank Position Sensor

Intake Air Pressure

Sensor

Angle Advances

When Lower

Coolant Temperature

Sensor

Angle Advances

When Lower

Compensation ROM

Compensation Value

of Each Pump

1. Basic target injection timing Determined based on the accel erator opening and engine speed.

2. Injection timing compensation a. Intake air pressure compensation

Basic target inje ction timing is compens ated by the intake air pres sure. Whe n the at mospheric pressure is low on a altitude, for instance, the injection timing angle is advanced.

b. Coolant temperature compensation

Basic target injection timing is compensated based on the coolant tem perature. When the coolant temperatu re is low, the injection timing angle is advanced.

LNW21AMF001101-X

3. Feedback control a. Calculation of actual injection timing

When relation between the compression TDC position and crank angle reference position signal is correct on the engine side and the relation between the injection waveform and cam angle signal is cor rect on the pump side, actual injection timing θn can be calculated by calculating the phase di fference θi between the crank angle refere nce position signal and c am angle signal.

Page 21

Engine Control System 1A-19

Idle Speed (P.N Range in A/T Vehicle) [r/min]

M/T A/T

Legend

1. Engine

2. Pump

3. Injection waveform

4. Cam angle signal

5. Crank angle reference positi on signal

6. Actual compression TDC

LNW21ASH001701

Engine speed at no load

Air conditioner system ON

Approx. 580 Approx. 650

Approx. 800 Approx. 870

b. Feedback control

Timing control valve duty ratio is cal culated so that the actual injection timing coincides the target injection timing.

Idle Speed Control

• Idle speed is controlled by increasing or decreasing the specified fuel injection amount value based on the signal from ECM (engine control module).

Operation

1. Feedback control When there is a difference between the target speed calculated by the E CM an d eng ine speed at the idle speed, the fuel injection amount is controlled by changing the signal to the electromagnetic spi ll va lv e and co ntrol s s o th at the engine speed coincides the idle speed.

2. Warm-up control Optimum fast idle engine speed is controlled at idling by the coolant temperature.

3. Estimated control Immediately after changing over the air conditioning switch, before the engine speed changes, the injection amount is changed by a constant amount to preven t change of idle speed by the change of load given to the engine.

Page 22

1A-20 Engine Control System Component Layout

Fuse Layout

[Fuse Box Label, In Glove Box]

[Fuse Box, Front Left of Radiator]

27 28

LNW21ALF000401-X

Legend

1. Spare fuse

No. Indication on label Capacity Devices connected

1 CONTROLLER 10A Control unit

HAZARD,HORN (12V) 15A

Hazard warning flashing lamp, horn

HAZARD,HORN (24V) 10A

3—10A—

AIR CON (12V) 10A Air conditioner

HEATER,AIR CON (24V) 15A Heater, air conditioner 5 FUEL, SEAT HEATER (24V) 10A Fuel, seat heater 6 ABS, HAB, RETARDER (24V) 15A ABS, HAB, retarder

Page 23

Engine Control System 1A-21

No. Indication on label Capacity Devices connected

7 ROOM LAMP 15A Room lamp 8 STOP LAMP 10A Stop lamp 9 POWER WINDOW (24V) 20A Power window

11 FOG.CORNER 10A Fog lamp, cornering lamp 12 ELEC.PTO (24V) 10A PTO switch (electric PTO) 13 WIPER,WASHER 15A Wiper, window washer 14 TURN 10A Turn signal lamp

17 MIRROR 10A Electrically operated mirror 18 CIGAR,AUDIO 10A Cigarette lighter, audio

21 AIR BAG 10A SRS airbag

TAIL.ILLUMI (12V) 15A

Tail lamp

TAIL.ILUMI (24V) 10A

GENERATOR (12V) 15A Generator

ELEC.PTO (24V) 20A PTO solenoid valve (electric PTO)

MIRROR HEAT (12V) 10A Heated side mirror

ENG.CONT (24V) 15A ECM

METER (12V) 10A

Meter

METER (24V) 15A

ENGINE STOP (12V) 10A Engine stop

HSA (24V) 10A HSA

22 STARTER 10A Starter 23 H/LAMP RH 10A Headlamp, RH 24 H/LAMP LH 10A Headlamp, LH

26 POWER WINDOW (12V) 30A Power window

External Fuse Box

No. Indication on label Capacity Devices connecte d

27 MARKER LAMP 10A Marker lamp 28 COND FAN 10A Condenser fan

HEATER (12V) 30A Heater

ENG CONTROLLER (24V) 30A ECM (except for turbocharged vehicles)

Page 24

1A-22 Engine Control System

Relay Layout

Relay Box No.2

Bracket

Spare Power Circuit

Relay Box No.1

Upper

Cooler Relay

No. Legend

12 V: On relay

24 V: C harge relay

2 Horn relay

Fuse & Relay Box

RightFront

LNW21ALF006101-X

12 V: ABS, VSV, FICD, EXH brake

24 V: Headlamp relay

4Tail relay

12 V: Headlamp relay

24 V: 4WD relay 6 Dimmer relay 7 Power window relay 8 Fog lamp relay

Page 25

No. Legend

9 Cornering lamp relay

10 Air conditioner thermo relay

12 V: C harge relay

24 V: Key on relay

12 Heater & air conditioner relay

24 V: PTO cut relay for electric PTO in fire engine (MT)

24 V: PTO solenoid relay for electric PTO (AT)

12 V: Exhaust brake cut relay (MT)

24 V: Idle on relay for fire engine (AT)

24 V: Idle stop, wiper relay (with CFS (clutch free system))

24 V: PTO solenoid relay for electric PTO (MT)

24 V: PTO buzzer relay for electric PTO (AT)

12 V: OD off relay (AT)

24 V: Idle keep relay for fire engine (AT)

Engine Control System 1A-23

24 V: Idle stop, radio relay (with CFS)

24 V: PTO main relay for electric PTO (MT)

24 V: Garbage relay for garbage collector (AT)

24 V: Indicator lamp relay for fire engine (AT)

24 V: Idle stop, engine control module relay (with CFS)

4WD relay

24 V: Idle stop, mirror relay (with CFS)

24 V: Full automatic air conditioner, high relay

24 V: Automatic air conditioner, high relay

24 V: Shift lock relay for fire engine (AT)

24 V: Shift relay for fire engine (AT)

24 V: PTO main relay for electric PTO (MT)

19 24 V: PTO solenoid relay for electric PTO (MT) 20 24 V: PTO cut relay for electric PTO (MT)

Page 26

1A-24 Engine Control System

Engine Component Layout

Legend

1. EGR valve

2. Crank position sensor (CKP sensor)

3. Intake throttle body

4. MAP sensor

5. NE sensor

6. SPV

7. Fuel temperature sensor (FT sensor)

8. Oil pressure SW

9. TCV

10. ROM

11. Coolant temperature sensor

LNW21ALF003001

Page 27

Circuit diagram

ECM wiring diagram (1)

Engine Control System 1A-25

D24

Pump Cam Position Sensor

Crankshaft Position Sensor

Vehicle Speed

Sensor

Cooler

Compressor

Freezer

Compressor

Key SW

1 Accelerator Position Sensor 2 Idle Up Volume 5 PTO Position Sensor

Coolant Temperature

Sensor

Fuel Temperature

Sensor

Intake Air Temperature

Sensor

Main Relay

Neutral SW

Inhibitor SW

Exhaust Brake SW

(A/T)

Clutch SW

(M/T)

Starter Relay

Warm-Up SW

ABS/ASR

ECU

Diagnostic SW

Idle SW

D13

B12

B11

A17 A20

A21 A19

A16

A10

C11

C10

C12

C15

ECM

D9 D16 D26

A11 D20 A15

D12

A22

D21

D10

D22

A13

D23

D19

A12

B10

Spill Valve

EDU

Timing Control Valve

EGR EVRV

TCM

Swirl Control

Check Engine Lamp

Spill Valve Relay

Glow Lamp

TECH 2

Exhaust Brake VSV1

Glow Relay

Stop Lamp Relay

Exhaust Brake Lamp

Intake VSV

Tachometer

VSV

ECM

: Engine Control Module

EDU

: Engine Driver Unit

EVRV

: Electric Vacuum Regulating Valve

TCM

: Transmission Control Module

VSV

: Vacuum Switching Valve

Intake Air

Pressure Sensor

C14

C5 D17

Pump

ROM

LNW21AXF000301-X

Page 28

1A-26 Engine Control System

ECM Wiring Diagram (2)

1.25 B/L

CKP

ROM

0.5

G/B

G/R

Engine Control Module (ECM)

Compensation ROM and NE Sensor are built in the Injection Pump

Sensor

0.5 W

B5 (+)

0.5 R

B11

()

Sensor

0.5 G

B6 (+)

B12

()

0.5 L

D13D3D17

LNW21ALF000701-X

Page 29

ECM Wiring Diagram (3)

Engine Control System 1A-27

AP (Accelerator Position) Sensor

2 1

Engine Control Module (ECM)

0.5

Y/B

C6 (Sensor Ground)

PTO Accelerator Sensor

0.5

R/B

C14

Signal

Idle Up Volume

0.5

Y/G

C10

Signal

0.5

G/O

C11

Signal

0.5

Y/R

(Sensor

Power)

LNW21ALF000501-X

Characteristics of Circuit

• Multiple DTC is generated when several troubles (failures) occur. When multiple sensors or switches share a ground, or an open wiring o r short occurs on the share power sup ply or ground, DTCs with respect to related sensors or switches are displayed. If several DTCs are displayed, it is necessary to inspect the shared power supply or ground for open wiring or short. The harness 1 shown above figure is the power common to the AP sensor and idle up volume, and the harness 2 is a common ground. In the event of open wiring in wire 1 or 2, DTC 24 and 31 are displayed at the same time. Like this, the case where two or more DTC’s are displayed is the multiple DTC.

• If multiple DTC24 and 31 a re di splayed , the power supply wire 1 or ground wire 2 must be checked.

DTC Sensor actuator (detection item)

24 Accelerator position

sensor

31 idle up volume

Connector not connected, harness open wiring, or short, failure of main unit

Page 30

1A-28 Engine Control System

ECM wiring diagram (4)

32 1

ECM

C-1 C-12 C-15 C-9 C-5

0.5

Y/G

0.3

0.5

BLU/

RED

GRN

SIG

Engine Coolant Temperature Sensor

GND

0.3

0.5

R/G

GRN

SIG

GND

Fuel Temperature Sensor

0.3

0.5

R/Y

GRN

SIG

Intake Air Temperature Sensor

GND

Sensor

Ground

0.5 W/

GRN

Intake Air Pressure Sensor

C-4

0.5

L/W

Characteristics of Circuit

• Multiple DTC is generated when several troubles (failures) occur. When multiple sensors or switches share a ground, or an open wiring o r short occurs on the share power sup ply or ground, DTCs with respect to related sensors or switches are displayed. If several DTCs are displayed, it is necessary to inspect the shared power supply or ground for open wiring or short. The harness 1 in above figure is a common ground for the engine coolant temperature sensor, fuel temperature senso r, intake air temperature sensor and intake air pressure sen sor. In the event of the open wiring in the wi re 1, DTC 21, 23, 41 and 32 are displayed at the same time. In the event of the open wiring in the wire 2, DTC 21 , 23, and 41 are displayed at the time. Like this, the case where two or more DTC’s are displayed is the multiple DTC.

LNW21ALF000601-X

• If multiple DTC21, 23, 41, and 32 are displayed, the ground wire 1 must be checked.

• If multiple DTC21, 23, and 41 are displayed, the ground wire 2 must be checked.

• If multiple DTC21 and 23 are displayed, the ground wire 3 must be checked.

DTC Sensor actuator (detection item)

21 Engine coolant

temperature sensor

23 Intake air temperature

sensor

Connector not connected, open wiring or short of harness,

41 Fuel temperature sensor 32 Intake air pressure

failure of main unit

sensor

Page 31

ECM Pinouts

ECM is installed in the c en ter c onsol e an d it s i npu t and output are made through 4 c onnectors of 26 pins, 16 pins, 12 pins and 22 pins respectively, 76 pins in total.

000000 - 0000

0000 24V

000000 0000

MADE IN JAP AN

Engine Control System 1A-29

Legend

1. Engine model, rated voltage

2. Denso parts No.

D13

D26

D14

C16

LNW21AMF000501

2. Isuzu parts No.

4. Fuel injection unit model

B12

A11

41151269110211312413514615716814115216317418519620721822923102411

1516171819202122

71829310

A22

34567891011

14 13 12

A12

No. Connected to No. Connected to

A1 EGR,EVRV A12 Intake throttle VSV

LNW21ASF000501

Page 32

1A-30 Engine Control System

No. Connected to No. Connected to

A2 Startar switch A13 Tech 2 communications (DLC) A3 Key switch A14 Not used A4 Not used A15 Accelator position signal output (A/T) A5 Exhaust brake cut signal (A/T) A16 Exhaust brake cut signal (A/T) A6 Cluch switch A17 P/N switch, neutral switch A7 Not used A18 Not used A8 Not used A19 Freezer switch

A9 Diagnostic switch (DLC) A20 Air conditioner switch A10 Idle position switch A21 Exhaust brake switch A11 Power system ground A22 Swirl control VSV

No. Connected to No. Connected to

B1 Not used B7 Stop lamp relay

B2 Warm-up switch B8 Q down (ASR)

B3 Exhaust brake operating signal B9 Exhaust brake answer signal (ASR)

B4 Not used B10 Tachometer output

B5 Crank position sensor (+) B11 Crank position sensor (–)

B6 Pump cam position sensor (+) B12 Pump cam position sensor (–)

No. Connected to No. Connected to

C1 Coolant temperature sensor (+) C9 Intake air pressure C2 Not used C10 Idle up volume C3 Sensor power (AP, PTO accelerator, Idle up

volume) C4 Sensor power (MAP) C12 Fuel temperature sensor (+) C5 Sensor ground (MAP, coolant temp., intake

temp., fuel temp.) C6 Sensor ground (AP, PTO accelerator, Idle up

volume) C7 Not used C15 Intake temperature sensor (+) C8 Not used C16 Not used

C11 Accelerator position sensor signal

C13 Not used

C14 PTO position sensor signal

No. Connected to No. Connected to

D1 Not used D14 Not used D2 Not used D15 Not used D3 Pump ROM communications D16 EDU fail signal input D4 Exhaust brake VSV1 D17 Pump ROM communications D5 Not used D18 Not used

Page 33

Engine Control System 1A-31

No. Connected to No. Connected to

D6 Accelerator position signal output (ASR) D19 Exhaust brake indicator lamp D7 Vehicle speed sensor signal D20 Injection output signal (EDU) D8 Not used D21 CHEK ENGINE lamp D9 Main relay D22 Glow indicator lamp

D10 Spill control valve relay D23 Glow relay D11 Not used D24 Battery power D12 Timing control valve D25 Not used D13 Signal ground D26 Power system ground

Strategy-Based Diagnostics

Strategy-Based System Diagnostics

The system diag nostic is a unifo rm approach to repai r all electrical/electronic (E/E) systems. In the E/E system, different from genera l vehicle problems, faults frequently occur along the steps shown as follows:

1. Initial stage:

• A single fault occurs for a short while and, therefore, the customer may miss it. In this stage, the customer complaint is unclear and the fault cannot be reprod uced. But, the ECM may have stored the fault. = Past fault

2. Middle stage:

• A single fault occurs for a short while but is observed intermittent ly. It always occurs und er certain conditions. The customer complaint (description of fault) is clear but fault occurrence conditions are unidentified. If you comprehend these conditions, you can reproduce the trouble. = Intermittent fault (intermittent)

3. Realistic fault:

• The fault occurs certainly and the customer complaint is realistic and clear. You can reproduce the fault. However, there may exist two or more causes. = Current fault

The diagnostic flow c an always be used to resol ve an E/E system problem and is a starting point when repairs are necessar y. Th e following steps will inst ruct the technician how to proceed with a diagnosis:

1. Verify the customer complaint:

• To verify the customer complaint, the technician should know the normal operation of the system.

2. Perform preliminary checks:

• Conduct a thorough visual inspection.

• Review the service history.

• Detecting unusual sounds or odors.

• Gather DTC (diagnostic trouble code) information using Tech 2

3. Check bulletins and other servic e information.

4. Refer to “Symptom Diagnosis Chart” in this manual.

• “Symptom Diagnosis Chart” contain information on a system that may n ot be support ed by one or more DTCs. “Symptom Diagnosis Chart” verify proper operation of the system. This will lead the technician in an organized approach to diagnostics.

5. Refer to related descriptions such as those for engine mechanicals.

DTC Stored

Follow the designated DTC chart exactly to make an effective repair.

No DTC

Select the symptom from the “Symptom Diagnosis Chart”. Follow to the diagnostic paths or suggestions to complete the repair. You may refer to the applicable components/system check in the functional check.

No Matching Symptom

1. Analyze the complaint.

2. Develop a plan for diagnostics.

3. Utilize the wiring diagrams and the theory of operation.

Call technical as si st anc e for s im il ar c as es wh er e repair history may be available. Combine technician knowledge with efficient use of the available service information.

Intermittents

Conditions that are not always present are call intermittents. To resolve intermittents, perform the following steps.

1. Observe history DTCs, DTC modes, and engine data.

2. Evaluate the symptoms and the condition described by the customer.

Page 34

1A-32 Engine Control System

3. Use a check sheet or othe r method to identify the circuit or electrical system component.

No Trouble Found

This condition exists when the vehicles is found to operate normally. The condition described by the customer may be normal. Verify the customer complaint against another vehicle that is operating normally. The condition may be interm ittent. Verify the complaint under the conditions described by the customer before releasing the vehicle.

1. Reexamine the complaint. When the compl aint cannot be suc cessfully found or isolated, a re-evaluation is necessary. The complaint should be re-verified and could be intermittent as defin ed in Inter mittents, or c ould be normal.

No. Item Objective Method

2. Repair and verify. After isolating the cause, the repairs should be made. Validate for proper operation and verify that the symptom has been corrected. This may involve road testing or other methods to verify that the complaint has been resolved under the following conditions:

• Conditions noted by the customer.

• If a DTC was diagnosed, verify a repair by duplicating conditions present when the DTC was set as noted by Tech 2 data.

Verifying Vehi cle Repair

When the electronic con trol syste m has been re paired, it is necessary to verify the repa ir is appropriate. If the repair is incomplete , the CHECK ENGINE Lam p (MIL) may be lit again while the vehicle is released, or the drivability may be impaired. Particularly for the intermittents, it is necessary to reproduce the trouble under the same conditi ons described by the custo mer and check the trouble is no longer found.

1 Verifying the

DTC

2 Verifying the idle

speed after warm-up

3 Verifying Tech 2

data list

4 Verifying the

restartability

5 Verifying the

electromagnetic compatibility of strong electric wave emission equipment

To check the DTC is not set after the repair.

To check the idle control is normally performed.

To provide basic checking for engine control and communication con di tio ns .

To check the start control correctly works.

To check electric wave emission equipment such as transceiver, if added, does not emit interfering waves.

Clear the previous DTC. Sufficiently warm up the engine under idling, and increase the engine speed to 2200 rpm and provide racing to verify the test conditions.

Upon completion of engine warm-up, verify the idle speed is 580 rpm for a manual transmission vehicle or 650 rpm for an automatic transmission vehicle with the air conditioner turned off. If a fault is detected, refer to "Instable idling" in " “Symptom Diagnosis Chart" to identify the cause.

Monitor Tech 2 data list and examine the data using typical value sheet. Check typical values in Tech 2 data list.

Upon completion of engine warm-up, verify the cranking time is not more than 5 seconds and the engine speed is stable after startup.

Turn on and off the electric wave emission equipment, such as transceiver, to check whether idle speed will change. If a problem is found, inform the customer that the electric wave emission equipment must be dislocated or changing the power is needed.

Supplementary d escription about strong electric wa ve emission equipment: If a problem is found in this checking, provide the following advices to the customer.

• To install the antenna away from the vehicle electronic system components such as control unit and sensor s as far as possible.

• To install the antenna cord at least 20 cm away from the vehicle electronic system components such as control unit and sensors.

• Do not arrange the antenna cord together with other cables. In additi on, isolate the antenna cord from other cables as far as possible.

• Install additional devices certainly according to respective instruction manuals.

• Do not install high-power mobile communication equipment.

Page 35

Engine Control System 1A-33

CAUTION: Follow the steps below when you verify repairs on OBD systems. Failure to follow these steps could result in unnecessary repairs.

1. Review and record Tech 2 data relative to the issued DTC.

2. Clear the DTC(s).

3. Operate the vehicl e while che cking t he associ ated Tech 2 data.

Non-OEM Parts

All of the OBD diagnostic s have been calib rated to run with OEM parts. There fore, installation of general onmarket sensors or switches are will result in incorrect OBD diagnostics and CHECK ENGINE Lamp (MIL) activation. If on-market electroni c de vices such as mobile phon es , stereos, and theft deterrent system are improperly installed, EMI (electromagnetic interference) radiation occurs and affects the control system. As a result, incorrect data are sent from sensors to turn on the CHECK ENGINE Lamp (MIL). To diagnose the vehicle with the OBD system, turn off or remove all the onmarket parts.

Poor Vehicle Maintenance

The sensitivity of OBD diagnostics will cause the CHECK ENGINE Lamp (MIL) to turn on if the ve hi cl e is not maintained properly. Restricted oil filters, fuel filters, and crankcase deposi ts due to lack of oil changes or improper oil viscosity can trigger actual vehicle faults that were not previously monitored prior to OBD diagnostics. Vehicle maintenance cannot be classified as "non-vehicle fault", but with the sensitivity of OBD diagnostics, vehic le maintenance schedules mu st be more closely followed.

Related System Faults

Many of OBD system diagnostics will not run if the ECM detects a fault on a related system or component.

Visual/Physical Engine Compartment Inspection

Perform a carefu l visual/physical engine co mpartment inspection when perfo rming dia gnostic pro cedure. Th is can often lead repairing a problem without further steps. Use the followi ng guidelines when per forming a visual/physical inspection.

• Inspect all vacuum hoses for punches, cuts, disconnects, and co rrec t rout in g.

• Inspect hoses that ar e difficult to see be hind other components.

• Inspect all harnesses in the engine compartment for proper connections, burned or chafed spots, pinched harnesses, contact with sharp edges or contact with hot exhaust manifolds or pipes.

Basic Knowledge of Tools Required IMPORTANT:

Lack of basic knowledge of this powertrain when performing diagnostic procedures could result in an incorrect diagnosis or damage to powertrain components. Do not attempt to diagnose a powertrain problem without this basic knowledge. A basic understanding of hand tools, including scan tool, is necessary to effectively use this section of the Service Manual.

On-Board Diagnostic Tests

The diagnostic test is a series of steps, the result of which is a pass or fail reported to the Diagnostic Executive. When a diagnostic test reports a pass result, the Diagnostic Executive records the following data:

• The diagnostic test has been co mpleted sinc e the last ignition cycle.

• The diagnostic tes t has passed durin g the current ignition cycle.

• The fault identified by the diagnostic test is not currently active.

When a diagnostic test reports a fail result, the Diagnostic Executive records the following data:

• The diagnostic test has been co mpleted sinc e the last ignition cycle.

• The fault identified by the diagnostic test is currently active.

• The fault has been active during this ignition cycle.

• The operating conditions at the time of the failure.

Comprehensive Component Monitor Diagnostic Operation

Comprehensive com ponent moni toring dia gnostics ar e required to operate the engine properly.

Input Components

Input components are monitored for circuit continuity and out-of-range values. This includes rationality checking. Rationality checking refers to indicating a fault when the signal from a sensor does not seem reasonable, i.e., accele rator positi on sensor (AP S) that indicates high throttle position at low engine loads or low voltage MAP (manifold absolute pressure). Input components may include, but are not limited to the following sensors:

• Intake air temperature (IA T) sensor

• Crank position (CKP) sensor

• Engine coolant temperature (ECT) sensor

• Intake air pressure (MAP) sensor

• Accelerator position (AP) sensor

• Fuel temperature (FT) sensor

• Vehicle speed (VS) sensor

Page 36

1A-34 Engine Control System

Output Components

Output components are dia gno se d for pr ope r res pon se to control module commands. Components where functional monitoring is not feasible will be monitored for circuit continuity and out-of-range values if applicable. Output components to be monitored include, but are not limited to, the following circuits:

•EGR EVRV

• Tra nsmission control

• Intake throttle

Terms Commonly Used in Diagnosis Diagnostic

When used as a noun, the word diagnostic refers to any on-board test run by the vehicle’s Diagnostic Management System. A diagnostic i s simply a test r un on a system or c omponent to determine if the system or component is operating according to specification. There are many diagnostics, shown in the following list.

• EGR (exhaust gas recirculation)

• Engine speed

• Vehicle speed

• ECT (engine coolant temperature)

• MAP (intake air pressure)

• VSV (Vaccum switching valve)

• IAT (intake air temperature)

• AP (accelerator position)

• FT (fuel temperature)

• Idle position switch

• Brake switch

by the diagnostic p rocedures c ontained in this manual. The language of communicating the source of the malfunction is a system of diagnostic trouble codes. When a malfunction is detect ed by the control modul e, a diagnostic trouble code is set and the CHECK ENGINE Lamp (MIL) is illuminated.

Malfunction Indicator Lamp (MIL)

The malfunction indicator lamp (MIL) looks the same as the MIL you are already familiar with ("Check Engine" lamp). Basically, the MIL is turned on when the electronic control system s uch as ECM (engine control modu le) fails and a DTC is detected.

Data Link Connector (DLC)

The provision of communication with the control module is the data link connector (DLC). The DLC is used to connect to Tech 2, or a scan tool. Some common uses of Tech 2 are listed below.

• Identifying stored diagnostic trouble codes (DTCs)

• Clearing DTCs

• Performing output control tests

• Reading serial data

Diagnostic Executive

The Diagnostic Executive is a unique segment of software that is designed to coordinate and prioritize the diagnostic procedures as well as define the protocol for recordin g and displaying their results. T he main responsibilities of the Diagnostic Executive are listed as following

• Commanding CHECK ENGINE Lamp (MIL) on and off

• DTC logging and clearing

• Tech 2 data recording

• Acquiring current status information on each diagnostic

Diagnostic Information

The diagnostic charts and functional checks are designed to locate a faulty circuit or component through a process of logi ca l d ec isio ns . T he ch ar ts ar e p re par ed with the requirement that the vehicle functioned correctly at the time of assembly and there are not multiple faults present. There is a continu ous self-diagnos is on certain co ntrol functions. This diagnostic capability is complemented

87654321

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LNW21ASH001801

Verifying Vehi cle Repair

Verification of vehicle repair will be more comprehensive for vehicles with on-board diagnostic (OBD) system diagnostic. Following a repair, the technician should perform the following steps:

1. Review and record DTC diag nosed o r Tech 2 data or both.

2. Clear DTC(s).

3. Operate the vehicle within the conditioned described by Tech 2 data.

Page 37

4. Monitor the DTC st atus info rmation for the spec ific DTC that has been diagnosed until the ECM performs the diagnostic test associated with that DTC.

Following these steps is very important in verifying repairs OBD systems. Failure to follow these steps could result in unnecessary repairs.

Diagnostic Trouble Code (DTC)

Whenever the starter switch is turned on, the ECM executes self-testing for almost wirings and components and, when detec ts a s ystem faul t, sto res i t and enables backup co ntrol according to the DTC set. When a fault occurs that will affect the running, the ECM turns on the CHECK ENGINE Lamp (MIL) in the meter panel or blinks the exhaust indicator lamp to inform the driver of the fact.

Reading Diagnostic Trouble Codes

Current and past DTCs stored to the ECM can be visualized in the form of blinking CHECK ENGINE Lamp (MIL) when the DLC (data link connector) is shorted. To this end, provide the following steps.

1. Turn on the key switch and check the CHECK ENGINE Lamp (MIL) is turned on. (Bulb check)

Engine Control System 1A-35

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LNW21ASH000301

4. On the CHECK ENGINE Lamp (MIL), read the number of blinks.

5. Identify the DTC from the DTC Chart.

Diagnostic Trouble Codes Not Stored

Code 12 that shows initiati on of i ndication is repeatedly displayed.

LNW21ASH000201

2. Keep the key switch turned on and the engine turned off.

3. Short pins 6 and 4 on the DLC. The DLC is a black 16-way connector and located at the lower right corner of the instrument panel.

Page 38

1A-36 Engine Control System

Diagnostic Trouble Codes Stored

Code 12 that is displayed three times and then stored code is displayed three ti mes. When multiple DTCs are stored, each code is displayed three times, starting from the lowest n umber. After all DTCs are displayed , above sequence is repeated from code 12 as l ong as DLC is being shorted.

eg.,) Display Start Cord "12"

Display Start

Turn On

Turn Off

eg.,) Trouble Cord "21"

Display Start

Turn On

urn Off

0.4 0.4

3.2

1.2

3.23.2 1.2

3.2

Unit (sec)

eg.,1 : Diagnostic Trouble Codes not Stored

12 12 12 12 12 12 12 12 12 12 12 12 12 12 12

eg.,2 : Diagnostic Trouble Codes "21", "24" Stored

12 12 12 21 21 21 24 24 24 12 12 12 21 21 21

Clearing Diagnostic Trouble Codes

When the system fails and the DTC is stored to the ECM, even repairing the faulty po rtion will not clea r the DTC from the memory. To clear the DTC, conduct the steps listed below.

• Keep the starter switch turned on and the engine turned off.

• Short the data link connector.

Perform the following steps.

1. Turn off the idle position switch for not less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

2. Turn on the idle position sw itch for not le ss than 1 second but not more than 3 seconds. (Release the

4. Turn on the idle position switch for not less than 1 second but not more than 3 seconds. (Release the accelerator pedal.)

5. Turn off the idle position swi tch for not le ss than 1 second but not more than 3 seconds. (Press the accelerator pedal.)

6. After the above operations are properly completed, the CHECK ENGINE L amp (MIL) illumi nates for 3 seconds to report the memory is cleared.

7. Turn off the starter switch. Wait for 5 seconds a nd turn on the starter switch again.

When Tech 2 ha s been connected to the vehicle, the DTC can be cleared through the memory clear operation with Tech 2.

accelerator pedal.)

3. Turn off the idle position switch for not less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

Endless Display

LNW21AMF000601-X

Page 39

Engine Control System 1A-37

Functional Check List

Hearing The objective is to comprehend the symptom completely based on the

customer complaint and provide accurate diagnostic.

On-Board Diagnosti c Syst em Check

Inactive CHECK ENGINE Lamp (MIL) Check

Active CHECK ENGINE Lamp (MIL) Check

The objective is to identify the faulty por tion on the electronic en gine control system. (Checking proc edu re )

The objective is to check the CHECK ENGINE Lamp (MIL) when it is not turned on even after ignition switch turn-on.

The objective is to check the C HECK ENGINE Lam p (MIL) is turn o n through the DTC is not set while the engine running

Engine is crank but will not run The objective is to check the engine is not started though it is cranked by

turning the starter switch

Hearing Diagnostic

1. Using the Engine Control System Diagnostic Chart, completely hear and comprehend the customer complaint. Reference:

Engine Control System Diagnostic Chart

When receiving the vehicle from the customer in the service factory, you must verify both the symptom and failure data using the Engine Control System

Diagnostic Chart. Proceed the process by focusing on the po ssible faulty system estimated from the fault (fact) instead of random hearing.

2. Judge the failure information accurately.

Comprehend the situation concretely based on 5W1H principle. Example: Low temperature, startup stage, permanent generation, vicinity of engine, metallic

sound, etc.

Key points on hearing

• What • Faulty event

• When • Date and time, generation frequency

• Where • Situation of road

• State • Running condition, driving condition, weather conditions

• Result • Feeling of fault

LNW21ASH001301

Legend

1. Symptom

2. Failure generation frequency and conditions

The reason why this sheet is needed is as follows.

1. The symptom may not be reproduced in the service factory.

2. The customer complaint is always not represent failure.

3. If failure conditions are not i npu t to the respo n sibl e technician correctly, unwanted repair man-hours will be generated.

• The Engine Control System Diagnostic Chart helps diagnostic, repair, and repair verification.

Page 40

1A-38 Engine Control System

Engine Control System Diagnostic Chart

Customer

Driver

Vehicle acceptance date

Registration No.

No engine start

Poor startability

Instable idling

Poor driveability

SymptomFault conditions

Engine stall

Vibration at idling

Data observed at fault occurrence

Fault generation frequency

No cranking No initial combustion Incomplete initial combustion

Long cranking (6 seconds or more)

Others

Incorrect idle speed (idle speed enters into typical range after warm-up)

Rough idling (idle speed deviates from the typical range after warm-up)

Surging

Unusual sound

Immediately after engine startup

At operation of A/C

At gear shifting

Engine has transverse vibration and body has vertical vibration (engine’s vertical vibration is weaker than body’s vibration)

Always

Others

Inspector:

Vehicle model and model year

Vehicle ID

Engine model

Engine ID

Engine type

Odometer reading km

Unusual idle speed High ( rpm) Low ( rpm)

Others

Knocking Engine vibrationExtensive black/white smoke

Others

At release of accelerator pedal

Immediately after engine oil replacement

Others

OnceOccasionally (cycles: times/month)

Weather

Temperature 30

Place

Engine temperature

Driving conditions

Check Engine lamp

Past

DTC

Present

Fault history

Clear Cloudy Rainy Snowy Combined/

C or above

Highway Suburban area

Rough road

Cold

Startup

Driving

A/C SW ON/OFF

Date (year/month/day)

Warm-up After warm-up Coolant temperature

C 10-15 C0C or below ( C)

20-30

Urban area Uphill slope Downhill slope

Others

Immediately after startup ( minutes) Idling Racing

Steady-speed driving Acceleration Deceleration

Others

Occasionally ON OFF

others

C Oil temperature C

LNW21AXF000701-X

Page 41

On-Board Diagnostic (OBD) System Check

Engine Control Module (ECM)

2345678

9 10111213141516

0.5

GR/W

Engine Control System 1A-39

A13

0.5 SB

Data Link Connector (DLC)

A/T SRS

Retarder

Circuit Description

The on-board diagnostic (OBD) system check is a starting point for any driveability complaint diagnosis. Before using this procedu re, perform a visual/physical check the ECM (Engine Control Module) ground for cleanliness and correct tightening. The OBD system check is an orgainzed approach to identifying a problem created by an electron ic engine control system malfunction.

Diagnostic Aids

An intermitted may be caused by a poor conne ction, a rubbed through wire in sulation, or a wire broke n inside the insulator. Check for the poor connection or damaged harness. Inspect the ECM harness and connector fo r improper mating, broken locks, improperly formed or damaged pin, poor pin-to-wire connection, and damaged harness.

LNW21ALF000901-X

Test description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

1. The CHECK ENGINE Lamp (MIL) should be “ON” steady while the starter switch is “ON” and engine “OFF”. If not “Inactive CHECK ENGINE Lamp (MIL)” check should be used to isolate the malfunction.

2. Check the communic ation data circuit and ensure s that the ECM is able to transmit serial data.

3. This test ensures that the ECM is capable of controlling the CHECK ENGINE Lamp (MIL) and the CHECK ENGINE Lamp (MIL) driver circuit is not shorted to ground.

4. If the engine will no t start, the Cranks But Will Not Run chart should be used to diagnose the condition.

7. A Tech 2 parameter that is not within the typical range may help to isolate th e area that is causing the problem.

Step Action V alue(s) Yes No

1. Starter switch "ON", and engine "OFF"

2. Observe the CHECK ENGINE Lamp

(MIL).

—

Go to "Inactive

CHECK ENGINE

Is the CHECK ENGINE Lamp (MIL) "ON"?

Go to Step 2

Lamp (MIL)”.

Page 42

1A-40 Engine Control System

Step Action V alue(s) Yes No

1. Starter switch "OFF"

2. Install the Tech 2.

3. Starter switch "ON".

4. Using Tech 2 , display ECM engine data.

—

Does the Tech 2 display engine data?

1. Remove the Tech 2 ,and short DLC (d ata link connector) pins 4 and 6.

2. Observe the CHECK ENGINE Lamp

(MIL).

Does the CHECK ENGINE Lamp (MIL) display "12"?

Start the engine. Does the engine start and continue running? Using Tech 2, select DTC. Are any DTC stored?

Is DTC 52 stored ?

Compare ECM data v alues displayed on the Tech 2 to the typical value engine scan data.

Are the displaye d values a standard or clo se to the typical value?

1. Starter switch "OFF", disconnect the ECM.

2. Starter switch "OFF", engine "OFF".

3. Check the communication data circuit for an open wiring, short to ground, or short to voltage. Also, check the DLC ignition feed circuit for and open wiring or short to ground and the DLC groun d circuit for an open wiring.

4. If a problem is detected, repair as necessary.

Go to Step 3 Go to Step 8

—

Go to Step 4

—

Go to Step 5

—

Go to Step 6 Go to Step 7

— Go to DTC 52

chart.

—

The OBD system

is in normal

condition

Go to “CHECK ENGINE Lamp (MIL) Remains

Active".

Go to "Engine

Cranks But Will

Not Run".

Go to the

appropriate DTC

Chart.

Refer to

"Diagnostic Aids"

Was a problem detected? Check the Tech 2 with another vehicle.

Is the Tech 2 in abnormal? Replace the ECM.

Is the action complete? Repair Tech 2 or prep aration f or an other Tech

Is the action complete?

Go to Step 2 Go to Step 9

—

Go to Step 11 Go to Step 10

—

Go to Step 2 —

—

Go to Step 2 —

Page 43

Inactive CHECK ENGINE Lamp (MIL)

Engine Control System 1A-41

Key

50A

Meter Panel

Starter

Glow Lamp

0.3O/L

D22 D21

3B/Y

Meter 15A

CHECK ENGINE Lamp

0.5Y/B

Engine Control Module (ECM)

Exhaust Brake Lamp

0.3BR/W

D19

Circuit Description

The CHECK ENGINE Lamp (MIL) should be “ON” steady while the sta rte r swi tc h (k ey swi tc h) is “ ON” and engine “OFF”. The ignition powe r voltag e is applie d to MIL through the meter fuse. ECM tur ns the MIL “ON” by connecting the MIL driver circuit to the ground.

Diagnostic Aids

An intermittent MIL “OFF” may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside the insulation. Check the following items.

• Inspect the ECM harness and connector for broken locks, improperly formed or dam aged pin, poor pin-to-wire connection, and damaged harness.

• When the engine is oper ating normally, c heck for burning out of the bulb, open wiring of MIL output circuit, or open wiring of the ignition power circuit.

LNW21ALF001001-X

• If the engine cranks but will not start, check for open wiring of the ECM ignition ON power or battery power circuit, or poor connection of the ECM and engine ground.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

2. If the “Inactive CHECK ENG IN E La mp ( M IL) wil l n ot start, ECM ignition supply fault or bat tery power circuit fault is considered.

9. Check each ECM ground pin with the test light connected to B+ to see if the ground condition is normal. For the pin pos iti on of the E CM gr ou nd ci rcui t, refer to "ECM pin allocation".

Page 44

1A-42 Engine Control System

Step Action V alue(s) Yes No

Was the "On-Board Diagnosis (OBD) System

Check" performed? Start the engine.

Is the engine start? Check the meter fuse for the instrument

cluster ignition power circuit. (Meter 15A)

Is the fuse in normal condition? Starter switch "ON". Connec t ground the test

light 5-8840-0632-0, and check the cluster

ignition power circuit.

—

Go to Step 2

Go to Step 3 Go to Step 7

Go to Step 4 Go to Step 17

Go to the "OBD

System Check"

Is the test light “ON”? Check the bulb for meter clus ter and CHECK

ENGINE Lamp (MIL).

Replace the bulb if broken. Was a problem detected?

1. Starter switch "OFF".

2. Disconnect ECM.

3. Connect the MIL driver c irc uit of the ECM

connector to the ground through a jumper.

4. Starter switch "ON". Is the malfunction indicator lamp (MIL) "ON"?

Check the ECM ignition power fuse, battery power circuit fuse, engine fuse and ECM fuse.

Is the fuse in normal condition?

1. Starter switch "OFF".

2. Disconnect the ECM.

3. Starter switch "ON".

4. Connect ground the test light 5-88400607-0, and check the ignition power circuit for the ECM harness connector.

Go to Step 5 Go to Step 14

—

Verify repair Go to Step 6

—

Go to Step 11 Go to Step 12

—

Go to Step 8 Go to Step 16

—

Is the test light “ON”? Connect ground the test li ght 5-8840-0607-0,

and check the battery B+ power circuit for the

ECM harness connector. Is the test light "ON"?

Check the ECM ground poor connection.

Was a problem detected? Check the ECM pin for damage.

Was a problem detected? Check the MIL driver circuit between ECM

and MIL for open wiring and poor connection.

Was a problem detected?

Go to Step 9 Go to Step 13

—

Go to Step 10 Go to Step 15

—

Verify repair Go to Step 11

—

Verify repair Go to Step 18

—

Verify repair Go to Step 19

Page 45

Engine Control System 1A-43

Step Action V alue(s) Yes No

Replace the "normal " relay for ECM main relay.

Was the malfunction corrected? Repair the ignition power circuit open wiring or

starter switch failure.

Is the repair complete? Repair the ECM battery po wer cir cuit fo r o pen

wiring.

Is the repair complete? Repair the ground short for ECM ignition

power circuit or ECM battery power circuit.

Is the repair complete? Repair the ground s hort for i nstrument c luster

of ignition power circuit , and replace the fuse.

Is the action complete? Replace the ECM.

Is the action complete? Check the CHECK ENGINE Lamp (MIL)

driver circuit for the instrument panel poor

connection. Was a problem detected?

—

Verify repair Go to Step 14

Verify repair —

Go to "Diagnostic

Verify repair

Aids"

Page 46

1A-44 Engine Control System CHECK ENGINE Lamp (MIL) Remains Active

Key

50A

Meter Panel

Starter

Glow Lamp

0.3O/L

D22 D21

3B/Y

Meter 15A

CHECK ENGINE Lamp

0.5Y/B

Engine Control Module (ECM)

Exhaust Brake Lamp

0.3BR/W

D19

Circuit Description

The CHECK ENGINE Lamp (MIL) should be “ON” steady while the starte r s witc h (ke y s wit ch ) i s "ON" and the engine “OFF”. The ignition power voltage is supplied to MIL throu gh the meter fuse. E CM is turns MIL "ON" by ground the MIL driver circuit. If the DTC is not set up while the engine is running, MIL does not keep ON. Wh en the engine is runni ng, DTC has been set up, and the MIL ke eps ON, ground shor t of the MIL driver circuit is considered.

Diagnostic Aids

An intermittent MIL “ON” may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside the insulation. Check the following items.

LNW21ALF001001-X

• Poor connection or damaged harness: Inspect the ECM harness and connector for improperly mating, broken locks, improperly formed or damage pin, poor pin-to-wire connection, and damaged harness.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

2. If the MIL “ON” continue lighting when the ECM disconnect, the MIL driver wiring is not faulty.

6. When the MIL driver circu it is norma l, the MIL dr iver wiring in the meter panel cluster is faulty.

Page 47

Engine Control System 1A-45

Step Action V alue(s) Yes No

Was the "On-board diagnosis (OBD) system

check" performed?

1. Starter switch "OFF", disconnect the ECM.

2. Starter switch "ON", and monitor the

CHECK ENGINE lamp (MIL).

—

Go to Step 2

Go to the "OBD

System Check"

Is the CHECK ENGINE Lamp (MIL) "ON"?

1. Starter switch "OFF", disconnect the instrument panel connector.

2. Check for the ground short for MI L driver

circuit between ECM and instrument panel cluster.

3. If a problem is detected, repair as necessary.

Does the ground short for MIL driver circuit? Replace the instrument panel cluster.

Is the action complete?

1. Starter switch "OFF", and re-connect the ECM.

2. Short DLC 4 and 6. Starter switch "ON".

Does the CHECK ENGINE Lamp (MIL) display DTC?

Replace the ECM. Is the action complete?

—

Go to Step 3 Go to Step 5

Go to the "OBD

System Check" Go to Step 4

Go to the "OBD

System Check" —

Go to the "OBD

System Check" Go to Step 6

Go to the "OBD

System Check" —

Page 48

1A-46 Engine Control System Engine Cranks But Will Not Run

1.25

Main Relay

W/R

EXH Brake Magnetic Valve

SP Valve Relay

TCV

1.25 Y/R

D12

0.5 G/R

D10 D16 D20

0.5 L/R

Engine Control Module (ECM)

0.5 G/W

EDU

High Voltage

Generating Circuit

Control

Circuit

EDU

SPV+

SPV

GND (Case)

SPV

Circuit Description

Fuel is injected by opening and closing the fuel high pressure circuit wit h th e S PV (sp il l cont ro l v al ve). ED U (engine driver uni t; high vo ltage driv er) is used to drive the SPV at a high speed. EDU attains high speed drive of SPV at a high fuel pressure with a high voltage, quick energizing system. If the EDU, ECM or SPV fails, the engine is crank but the initial explosion do es not take place.

Diagnostic Aids

An intermittent problem may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check the following items.

C A B

D E F

LNW21ALF000801-X

• Poor connection or damaged harness: Inspect the ECM harness and EDU harness connector for improper mating, broken locks , improperly form ed or damage pin, poor pin-to-wire connection, and damaged harness.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

4. An obvious cause of lo w fuel pressur e would be an empty fuel tank.

9. In case of open wiring or short of the EDU circuit, set DTC 53.

Page 49

Engine Control System 1A-47

Step Action V alue(s) Yes No

Was "On-board diagnosis (OBD) system

check" performed? Check the 50A ECM f use, 50 A KEY SW fus e,

10A control fuse and the 15A control fuse.

Was the fuse blown? Check for a short t o ground, and replace the

fuse.

Is the action complete? Is the fuel tank empty?

Is a proper fuel used (use dehumidifying

agent is not advisable)? Using Tech 2.

Set the DTC 11? Using Tech 2.

Set the DTC 13? Using Tech 2.

Set the DTC 16? Using Tech 2.

Set the DTC 53? (Does the check for EDU circuit defective?)

Using Tech 2.

Set the DTC 52?

1. Refer to engine mechanical diagnosis to diagnose the following conditions.

• Faulty camshaft gear

• Leaking valve or ring

• Excessive valve deposits

• Weak valve spring

• Incorrect valve timing

• Leaking head gasket

• Excessive fuel filter deposits

2. If a problem is detected, r epair or replace as necessary.

—

Go to Step 2

Go to Step 3 Go to Step 4

Verify repair —

Replenish to the

fuel tank Go to Step 5

Go to Step 6 Replace the fuel

Go to DTC 11 Go to Step 7

Go to DTC 13 Go to Step 8

Go to DTC 16 Go to Step 9

Go to DTC 53 Go to Step 10

Go to DTC 52 Go to Step 11

Go to the "OBD

System Check"

Was a problem detected? Replace the ECM.

Is the action complete?

Verify repair Go to Step 12

—

Verify repair —

Page 50

1A-48 Engine Control System Diagnosis with Tech 2 Scan Tool

T ech 2 Scan Tool

Tech 2 is an effective tool for diagnosis of electrical failures on the engine co ntrol system. Thi s scan tool is a small and lightweight handheld tester and, once connected to the DLC on a vehicle, c omm uni cates with the on-board ECM to per form various diagnostics and tests.

Legend

1. PCMCIA card

2. Tech 2

Features of Tech 2

• Tech 2 (2) is operated at 12 V. Therefore, 24-V power supply must n ot be used for this tool . If the vehicle electrical system rating is 24 V, the adapter must be connecte d t o a 1 2 V batte ry. Tech 2 mus t not be powered by the cigarette lighter.

LNW21ALF000201

3. DLC cable

4. SAE 16/19-pin adapter

• Insert the PCMCIA card (1) into Tech 2. Then, connect the DLC cable (3) and SAE 16/19-pin adapter (4) to the VCI (vehicle communication interface) of Tech 2 and connect Tech 2 to the DLC on the vehicle.

• Insert or remove the PCMCIA card with the power supply turned off.

Page 51

Engine Control System 1A-49

• Tech 2 supports two snapshot capacities.

• The PCMCIA card is susceptible to magnetism and static electri city and, therefore, c omplete care should be taken in handling.

• Tech 2 can plot snapshot graphs.

• Hitting the Exit key allows you to return to the main menu at any time.

• To clear DTC(s), you should open the applic ation menu and select "F1: Clear DTC Info" or "Clear DTC".

Connection

1. I nsert the ISUZU System PCMCIA card into Tech

2. Install the SAE 16/19-pin adapter to the DLC cable.

3. Connect the DLC cable to Tech 2.

4. Check the starter switch is turned off.

5. C onnect the Tec h 2 SAE 16/19- pin adapter to the DLC (data link connector = black) on the vehicle.

Connect Tech 2 and 12 V batter y with an adapter cable.

LNW21ASH001401

• If the voltage is not applied to Tech 2, check the 3 A fuse.

6. Turn on the starter switch and press the PWR key on Tech 2.

7. Check the following sc reen app ears on the Tec h 2 display.

87654321

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LNW21ASH001801

Press (ENTER) To Continue

RUW16ESH001501-X

CAUTION: Before inserting or removing the PCMCIA card, always check the power is not applied to Tech 2.

Page 52

1A-50 Engine Control System

Operatin g Procedure

Press (ENTER) To Continue

(ENTER)

Vehicle Identification

Select one of the following

(N*) ELF, NPR, NQR, VFR

(ELF, NPR, NQR, VFR ENTER)

System Selection Menu

Main Menu

F0 : Diagnostics

F1 : Service Programming System (SPS)

F2 : View Capture Data F3 : Tool Options F4 : Down load/Up load Help

(F0 ENTER)

Vehicle Identification

Select one of the following

Model Year(s)

(3)

2003

(2)

2002

(1)

2001

(Y)

2000

(X)

1999

(W)

1998

(2)

2002

(2002 ENTER)

(N*) ELF, NPR, NQR, VFR

F0 : Engine

F1 : Transmission

F2 : Chasis

F3 : Boody

(F0 ENTER)

Vehicle Identification

Select one of the following

Eingine

Denso 4H* 4JHI-TC Bosch 4HL1/4HJ1(COMMON RAIL) 4HL1/4HJ1(

Vehicle Interface Module

4HE1-TC (Diesel)

(4HL1/4HJ1(COMMON RAIL) or 4HL1/4HJ1(Vehicle Interface Module) ENTER)

)

LNW21ALH000101-X

RUW16ELH000101-X

Menu List

• The list below shows what function is currently used by the Tech 2 software.

F0: Diagnostic Trouble Codes

F0: Read DTC Info As Stored By ECU

F1: Clear DTC Information F1: Data Display F2: Snaphot

Page 53

Engine Control System 1A-51

Menu Breakdown Diagnostic Trouble Codes

• When you find a DTC, go to the DTC Chart.

Diagnostic Trouble Codes

F0 : Read DTC Info As Stored By ECU

F1 : Clear DTC Information

LNW21ASH001501-X

The DTC is a lang uage allowing you to commun icate with the on-board ECM. The DTC is coarsely divided into two categories, past DTC and current DTC.

• Current DTC: A fault (failure) is displayed that is found in the current ignition cycle.

• Past DTC: A fault (failure) is displayed that was found in the last or past ignition cycle.

• Multiple DTC is generated when several troubles (failures) occur. When multiple sensors or switches share a ground, or an open wiring o r short occurs on the shared power supply or ground, DTCs with respect to related sensors or switches are displayed. If several DTCs are displayed, it is necessary to inspect the shared power supply or ground for open wiring or short. Usin g DTC clear mode erases the vehic le D TC info r mati on f rom the ECM.

Data Display

• Typical values are described in the Tech 2 data list.

Data Display

Battery Voltage

Accelerator Sensor

Turbo

Intake Air Temperature

Fuel Temperature Sensor

Fuel Temperature

Battery Voltage

Select

Items

DTC

Quick

Snapshot

LNW21ASH009301-X

kPa

This menu displays the current data. The contents synchronize with the vehicle status. For example, th e engine coolant temperature sensor is monitored and displayed on the screen an d, if the engi ne is idling, the temperature on the screen will be changed accordingly.

• When you cannot select this data display menu: A fault presents on the cable between ECM and DLC.

• When an unusual value appears fixe d ly: Example - If the engine coolant temperature displayed is fixed to –40°C or +140°C, the possible cause is faulty ECT sensor, open wiring, or short. When moving conne ctors or wiring ha rnes ses with hands changes the display, poor pin connection, improper pin layout, broken harness wires, or short is a cause and, therefore, repair is needed.

• When "✻" appears instead of value: The Tech 2 software is faulty. If even one asterisk is observed instead of data on the display, the PCMCIA card needs version up.

Snapshot

• The snapshot mode records menus on the data list and plots graphs.

• Using this mode, you can reproduce and record customer’s claimed conditions and find faulty engine data.

• You can replay the recorded data with the commercial power applied to home outlets.

Page 54

1A-52 Engine Control System

• In the snapsho t after dete rminatio n of tri gger type , you can record the dat a ob tai ned whe n th e DT C is displayed. Reviewing this data can reveal the cause of failure.

Snapshot Plot

12345

ECT Desired Idle Speed Engine Speed

RUW16ESH001601

Snapshot After Data Indication

1. Select "Data Display" from the application menu.

2. A fter the vehicle data appears, select "Snapshot" at the screen bottom.

3. After the elapse of some time, press the Exit key.

4. Th e screen changes. After "Continue" app ears at the bottom, select "Continue".

5. After "Plot" appears at the bottom, select "Plot".

6. The menu select screen appears. Move to the desired item and press the Enter key until three items are select ed. Then, select "Approve" at the bottom.

7. A graph is plotted on the screen.

Snapshot After Determination of Trigger Type

1. Select "Data Display" from the application menu.

2. After items appears on the screen, select the desired item.

3. After the snapshot option screen appears, determine the trigger type and select "Record Snapshot" at the bottom.

4. When "Standby" blinks at the upper right of the screen, select "Trigger" at the bottom.

5. Verify the trigger type.

6. The screen chang es. After "Continue" appea rs at the bottom, select "Continue".

7. After "Plot" appears at the bottom, select "Plot".

8. The menu select screen appears. Move to the desired item and press the Enter key until three items are selec ted. Then, select "Approv e" at the bottom.

9. A graph is plotted on the screen.

Replaying Recorded Data Graph

1. Turn on Tech 2 and select "Snapshot data" displayed thereafter.

2. Check snapshot data titles appear on the screen.

3. Select the desired snapshot data title.

4. The data appears on the screen. To access the graph, select "Plot" at the bottom.

5. Menu select scre en appears. Move to th e desired item and press the Enter key until three items are selected. Then, select "Approve" at the bottom.

6. The graph is plotted on the screen.

Te ch 2 Typical Data Values

The data list is used to check the condition of the vehicle (engin e). The reference values (typic al values) are compared to the data acquired from the actual vehicle to determine the curren t situation, fo r example, temporary or permanent deviation, so that you can diagnose the vehicle (engine) and think out appropriate repar plan. (The menu in y our Tech 2 may differ from that shown above due to software version. Also, the menu may be changed without prior notice.)

Tech 2 Data Display Unit

Typical value at idling. Complete

warm-up, air temperature 20°C Battery Voltage V 23 ~ 26V Accelerator Sensor V 0.41 ~ 0.45V Turbo (MAP Sensor) V Depending on engine condition Turbo (MAP) kPa Depending on engine condition Intake Air Temperature °C Approx. 0 ~ 30°C depending on the

temperature around the engine.

Fuel Temperature Sensor V Approx. 2.35V depending on the

temperature around the engine.

Value at

diagnosis

Val ue after

check

Page 55

Engine Control System 1A-53

Tech 2 Data Display Unit

Typical value at idling. Complete

warm-up, air temperature 20°C Fuel Temperature °C Depending on the temperature

around the engine. Coolant Tempe ra ture Sens or V 1.38 ~ 1.68V Coolant Temperature °C 80 ~ 100°C PTO Sensor V 0V Barometric Pressure V Approx. 3.3V Idle-Up Sensor V Approx. 3.3 ~ 0.45V Engine Speed rpm Approx. M/T: 580rpm, A/T : 650rpm Final Accelerator Opening % 0% PTO Accelerator Opening % 0% Vehicle Speed km/h 0km/h ASR Accelerator Opening % 100% Corrected Fuel Injection Amount mm Final Fuel Injection Amount mm

/stk Approx. 12.6mm3/stk

/stk Approx. 61.3mm3/stk

Target Rotation Speed rpm Approx. M/T: 580rpm, A/T : 650rpm

Value at

diagnosis

Val ue after

check

Fuel Spill Open Valve Angle °CA Approx. 92°CA Fuel Spill Close Valve Angle °CA Approx. 56°CA Fuel Injection Timing °CA 5°CA Crank Angle Timing °CA 5°CA TCV Duty Cycle % 50 ~ 60% Cylinder 1 Compensation °CA ±1°CA or less Cylinder 2 Compensation °CA ±1°CA or less Cylinder 3 Compensation °CA ±1°CA or less Cylinder 4 Compensation °CA ±1°CA or less EGR Duty Cycle % Depending on engine condition Starter Switch (S) On/Off Off Neutral Switch On/Off Depending on the switch condition Diagnostic Switch On/Off Depending on the switch condition Key Switch (On) On/Off On Idle Switch On/Off On AC Switch On/Off Depending on the switch condition Clutch Switch On/Off Depending on the switch condition Exhaust Brake Switch On/Off Depending on the switch condition Exhaust Brake (AT) Cutoff Switch On/Off Off Exhaust brake (ASR) Cutoff

On/Off Off

Switch PTO Switch On/Off Depending on the switch condition Idle Speed Control On/Off On Engine Stop Switch On/Off Off

Page 56

1A-54 Engine Control System

Tech 2 Data Display Unit

Typical value at idling. Complete

warm-up, air temperature 20°C

Value at

diagnosis

Val ue after

check Engine Start On/Off Off Accelerator Switch On/Off Off Fuel Inj. Amount Limit (Injection) On/Off Off TCV Feedback On/Off On Thermo Switch On/Off Depending on the switch condition Exhaust Press. Valve 1 On/Off Off Glow Time Lamp On/Off Off Glow Time Relay On/Off Off Starting Counter (Counts) Varying depending on the count of

starter operations

Copy this table and use for measurement. • Typical value with starter switch ON (Engine

stops.)

Display on Tech 2 Unit

Typical value at idling. Complet e

warm-up, air temperature 20°C

Value at

diagnosis

Value after

confirmation Battery Voltage V 23 ~ 26V Accelerator Sensor V 0.41 ~ 0.45V Turbo (MAP Sensor) V Depending on engine condition Turbo (MAP) kPa Depending on engine condition Intake Air Temperature °C Approx. 0 ~ 30°C depending on the

temperature around the engine.

Fuel Tempe ratur e Sensor V Approx. 2.39 V depe nding on t he

temperature around the engine.

Fuel Temperature °C Depending on the temperature

around the engine. Coolant Temperature Sensor V 1.80 ~ 2.05V Coolant Temperature °C 0 ~ 30°C PTO Sensor V 0V Barometric Pressure V Approx. 3.3V Idle-Up Sensor V Approx. 3.3 ~ 0.45V Engine Speed rpm 0rpm Final Accelerator Opening % 0% PTO Accelerator Opening % 0% Vehicle Speed km/h 0km/h ASR Accelerator Opening % 100% Corrected Fuel Injection Amount mm Final Fuel Injection Capacity mm

/stk —

/stk — Target Rotation Speed rpm Approx. M/T: 580rpm, A/T : 650rpm Fuel Spill Open Valve Angle °CA Approx. 83°CA Fuel Spill Close Valve Angle °CA Approx. 56°CA

Page 57

Engine Control System 1A-55

Display on Tech 2 Unit

Fuel Injection Timing °CA 1°CA Crank Angle Timing °CA 1°CA TCV Duty Cycle % 0 ~ 1% Cylinder 1 Compensation °CA ±1°CA or less Cylinder 2 Compensation °CA ±1°CA or less Cylinder 3 Compensation °CA ±1°CA or less Cylinder 4 Compensation °CA ±1°CA or less EGR Duty Cycle % Depending on engine condition Starter Switch (S) On/Off Off Neutral Switch On/Off Depending on the switch condition Diagnostic Switch On/Off Depending on the switch condition Key Switch (On) On/Off On Idle Switch On/Off On AC Switch On/Of f Depending on the switch condition Clutch Switch On/Off Depending on the switch condition

Typical value at idling. Complet e

warm-up, air temperature 20°C

Value at

diagnosis

Value after

confirmation

Exhaust Brake Switch On/Off Depending on the switch condition Exhaust Brake (AT) Cutoff Switch On/Off Off Exhaust Brake (ASR) Cutoff

Switch PTO Switch On/Off Depending on the switch condition Idle Speed C ontrol On/Off On Engine Stop Switch On/Off Off Engine Start On/Off Off Accelerator Switch On/Off Off Fuel Inj. Amount Limit (Injection) On/Off Off TCV Feedback On/Off On Thermo Switch On/Off Depending on the switch condition Exhaust Press. Valve 1 On/Off Off Glow Time Lamp On/Off Off Glow Time Relay On/Off Off Starting Counter (Counts) Varying depending on the count of

On/Off Off

starter operations

Copy this table and use it for measurement. Typical values with the starte r switch ON may vary dep ending on the previous operating conditions.

Display on Tech 2 Unit

Battery Voltage V 23 ~ 26V Accelerator Sensor V 1.52 ~ 1.55V

Typical value at idling. Complet e

warm-up, air temperature 20°C

• Typical value at 1500rpm

Value at

diagnosis

Value after

confirmation

Page 58

1A-56 Engine Control System

Display on Tech 2 Unit

Typical value at idling. Complet e

warm-up, air temperature 20°C Turbo (MAP Sensor) V Depending on engine condition Turbo (MAP) kPa Depending on engine condition Intake Air Temperature °C Approx. 0 ~ 30°C depending on the

temperature around the engine.

Fuel Tempe ratur e Sens or V Approx. 2.35V dependi ng on the

temperature around the engine.

Fuel Temperature °C Depending on the temperature

Value at

diagnosis

Value after

confirmation

Vehicle Speed km/h 0km/h ASR Accelerator Opening % 100% Corrected Fuel Injection Amount mm Final Fuel Injection Amount mm

/stk —

/stk — Target Rotation Speed rpm Approx. M/T: 580rpm, A/T : 650rpm Fuel Spill Open Valve Angle °CA Approx. 90°CA Fuel Spill Close Valve Angle °CA Approx. 56°CA Fuel Injection Timing °CA 11°CA Crank Angle Timing °CA 11°CA TCV Duty Cycle % 60 ~ 70% Cylinder 1 Compensation °CA ±1°CA or less Cylinder 2 Compensation °CA ±1°CA or less Cylinder 3 Compensation °CA ±1°CA or less Cylinder 4 Compensation °CA ±1°CA or less EGR Duty Cycle % Depending on engine condition Starter Switch On/Off Off Neutral Switch On/Off Depending on the switch condition Diagnostic Switch On/Off Depending on the switch condition Key Switch On/Off On Idle Switch On/Off Off AC Switch On/Of f Depending on the switch condition Clutch Switch On/Off Depending on the switch condition Exhaust Brake Switch On/Off Depending on the switch condition

Page 59

Engine Control System 1A-57

Display on Tech 2 Unit

Exhaust Brake (AT) Cutoff On/Off Off Exhaust Brake (ASR) Cutoff On/Off Off PTO Switch On/Off Depending on the switch condition Idle Speed C ontrol On/Off On Engine Stop Switch On/Off Off Engine Start On/Off Off Accelerator Switch On/Off Off Fuel Inj. Amount Limit (Injection) On/Off Off TCV Feedback On/Off On Thermo Switch On/Off Depending on the switch condition Exhaust Press. Valve 1 On/Off Off Glow Time Lamp On/Off Off Glow Time Relay On/Off Off Starting Counter (Counts) Varying depending on the count of

Typical value at idling. Complet e

warm-up, air temperature 20°C

starter operations

Value at

diagnosis

Value after

confirmation

Copy this table and use it for measurement. Typical values at 1500rpm may vary depending on conditions.

Page 60

1A-58 Engine Control System

T ech 2 Data Description

Item Tech 2 Data Display Unit Description How to use parameters 1/52 Battery Voltage V Indicates voltage applied to

ECM. Difference from the actual battery voltage may be caused due to loads in the circuit, slight resistance value at the harness or conne ctor pin or other causes.

2/52 Accelerator Sensor V Indicates a signal value from

the accelerator position (AP) sensor. ECM reads the signal from AP sensor and indicates it. Voltage is applied from ECM to the AP sensor and ECM reads the accelerator pedal opening from varying sensor signal.

3/52 Turbo

(Intake Air Pressure Sensor)

V Indicates the signal value of the

intake air pressure (MAP). Voltage from ECM is applied to the MAP sensor and ECM reads the intake air pressure from varying signal of the sensor and indicates that value.

When the difference from the actual battery voltage is significant, any accessory attached to the circuit is considered as a cause, which may have droppe d the vol tage. If the value is out of the standard range, circuit, connector, connector mating, or ECM may have some fault.

When the value of the AP sensor (pedal opening) becomes out of the standard value according to the accelerator pedal stepping stroke, some fault has occurred in the sensor, circuit, throttle valve or ECM. Check the sensor, circuit, accelerator pedal and ECM in such a case.

If the signal value (pressure display) from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

4/52 Turbo (Intake Air Pressure) kPa Voltage from ECM is applied to

the intake air pressure (MAP) sensor and ECM reads the intake air pressure from the change of the sensor signal. The signal read by ECM is converted to pressure and indicated.

5/52 Intake Air Temperature °C Indicates the intake air

temperature. Using a thermistor type sensor which is characterized by a feature that the electric resistance decreases with increase of the intake air temperature, voltage i s applied from ECM to the IAT sensor, and ECM receives signal from the sensor, calculates and indicates the result. In the event of a fault oc curring in the sensor or circuit, the ECM performs failsafe by the backup value.

If the signal value (pressure display) from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

If the signal value (temperat ure display) from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

Page 61

Engine Control System 1A-59

Item Tech 2 Data Display Unit Description How to use parameters 6/52 Fuel Temperature Sensor V Indicates the signal value of

fuel temperature sensor. Voltage is applied from ECM to the fuel temperature sensor and ECM reads the fuel temperature from the varying sensor signal and indicates it.

7/52 Fuel Temperature °C Indicates the fuel temperature.

Using a thermistor type sensor which is characterized by a feature that the electric resistance decreases with increase of the fuel temperature, voltage i s applied from ECM to the fuel temperature sensor, and ECM receives signal from the sensor, calculates and indicates the result. In the event of a fault oc curring in the sensor or circuit, the ECM performs failsafe by the backup value.

8/52 Coolant Temperature

Sensor

V Indicates the signal value of the

coolant temperature sensor. Voltage is applied from ECM to the coolant temper ature sen sor and ECM reads the engine coolant temperature from the varying sensor signal and indicates it.

Various control conditions (at start, low temperature, after warm-up, etc.) are checked based on the fuel tem perature. May be used as con ditions for DTC detection.

If the signal (temperature display) from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

Various control conditions (at start, low temperature, after warm-up, etc.) are checked based on the engine coolant temperature. May b e used as conditions for DTC detection.

9/52 Coolant Temperature °C Indicates engine coolant

temperature. Using a thermistor type sensor which is characterized by a feature that the electric resistance decreases with increase of the coolant temperature, voltage i s applied from ECM to the coolant temperature sensor, and ECM receives signal from the sensor, calculates and indicates the result. In the event of a fault oc curring in the sensor or circuit, the ECM performs failsafe by the backup value.

If the signal value (temperat ure display) from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

Page 62

1A-60 Engine Control System

Item Tech 2 Data Display Unit Description How to use parameters

10/52 PTO Sensor V Indicates the signal value of

PTO accelerator opening sensor (all speed accelerator sensor). ECM reads the s ignal from the PTO accelerator sensor and indicates. Voltage from ECM is applied to the sensor and ECM reads the accelerator pedal ope ning from the varying signal from the sensor.

11/52 Barometric Pressure V Indicates signal value of the

barometric pressure sensor. Voltage from ECM is applied to the sensor installed in ECM and ECM reads the varying signal value and indicates it.

12/52 Idle Up Sensor V Indicates the signal value of the

idle up volume (idling speed adjusting switch). Voltage from ECM is applied to the sensor and ECM adjusts the idling speed based on the varying signal.

If the value of the sens or is out of the standard range according to the accelerator opening, some fault has occurred in the sensor main unit, circuit, throttle valve or ECM. Check the sensor, circuit, accelerator pedal or ECM in such a case.

Various control conditions (fuel injection amount control) are checked based on the barometric pressure. If the signal value from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

If the signal from the am ount is out of the standard range, some fault has occurred in the sensor, circuit, or ECM. Check the sensor, circuit, or ECM in such a case.

13/52 Engine Speed rpm Engine speed is calculated

based on the signal from the NE censer and CKP sensor. While the engine is idling, the engine speed follows up the target rotating speed and is stabilized. The NE sens or and CKP sensor generates electromotive voltage by the magnetic force and ECM incorporates that voltage as a signal.

14/52 Final Accelerator Opening % Indicates the accelerator pedal

opening. ECM reads the signal from the AP sensor and converts the signal read to opening.

Use the engine speed data comparing with the target rotating speed, while the engine is warming up and its idling speed is sta ble as the air conditioning system, etc. are OFF. The engine speed becomes stable around the target rotating speed. When the air conditioning system or other load is applied, the engine rotating speed is changed but stabilized.

Page 63

Engine Control System 1A-61

Item Tech 2 Data Display Unit Description How to use parameters

15/52 PTO Accelerator Opening % Indicates the opening of the

PTO accelerator. ECM reads the signal from the PTO accelerator sensor and converts the signal read to opening.

16/52 Vehicle Speed km/h ECM receives signal (pulse)

from the vehicle speed sensor, calculates the vehicle speed based on the signal and indicates the result.

17/52 ASR Accelerator Opening % On a vehicle equipped with

ASR, when the ASR operates, it controls the opening of the accelerator to decrease the engine speed. Indicates the accelerator opening control value. It is usually 100% and decreases as the ASR operates.

18/52 Corrected Fuel Injection

Amount

/stk ECM cont rols the fuel injection

and correct the fuel injection amount for each engine (fuel amount necessary for hipressurization). It indicates fuel amount required to obtain the target fuel pressure at the time of injection depending on the engine condition. ECM indicates a value calculated from the spill control valve, engine speed, etc.

19/52 Final Fuel Injection Amount mm

/stk Indicates fuel injection amount

from the injector. ECU calculated the amount of pressurized fuel from the condition of the timing control valve and spill control valve and indicates the calculation result.

If the signal value from the sensor is out of the standard value, some fault has occurred in the sensor, circuit or ECM. Check the sensor, circuit or ECM in such a case.

If the indication is different fro m the reading on the speedometer, or if the indication does not change, any fault ma y be i n the vehicle speed sensor, circuit or ECM.

If the value does not change, poor communicati on with ABS/ ASR control unit, ABS/ASR failure system, faulty ECM or ABS/ASR control unit, or fault in the circuit is the cause. Check them in such a case.

If the value is out of the standard range, any fault is in the spill control valve, vehicle speed sensor, circuit or ECM. Check the valve, sensor, circuit and ECM.

If the value is out of the standard range, any fault is in the spill control valve, timing control valve, vehicle speed sensor or circuit or ECM. Check the valves, sensor, circuits and ECM.

20/52 Target Rotation Speed rpm Idle speed calculated and

indicated by ECM. ECM corrects and c alculates t he idle speed from the coolant temperature or engine load and indicates the result as the specified idle speed.

If the required id le speed does not stabilized, improper installation of ECM or sensors (improper mating of co nnector, bent pin, etc.) or incorrect signal of ECM o r sensors may be considered. If the harness does not stabilize when vibration is given, fault of the harness, floating of the ground circuit, or poor connection of the connector is considered.

Page 64

1A-62 Engine Control System

Item Tech 2 Data Display Unit Description How to use parameters

21/52 Fuel Spill Open Valve

Angle

22/52 Fuel Spin Close Valve

Angle

°CA Ind icates the valve open timing

when the spill control valve is controlled. ECM opens or closes the valve to obtain the fuel pressure required for injection and calculates and indicates the timing from the engine condition. ECM calculates the various timing of the engine based on the signals from the CKP sensor and NE sensor.

°CA Ind icates the va lve close t iming

If the value is out of the standard range, any fault is in the timing control valve, sensors or, circuit or ECM. Check the valves, sensors, circuits and ECM.

If the value is out of the standard range, any fault is in the timing control valve, sensors or circuit or ECM. Check the valves, sensors, circuits and ECM.

23/52 Fuel Injection Timing °CA Indicates the valve opening

timing when the timing control valve is controlled. ECM opens or closes the valve to adjust the injection timing and calculates and indicates the timing from the engine condition. ECM calculates the target injection timing based on the signals from the accelerator opening, CKP sensor and NE sensor.

24/52 Crank Angle Timing °CA Indicates the actual fuel

injection timing. ECM opens or closes the v alve to adjust the injection timing properly and calculates and indicates the timing from the engine condition (target injection timing). ECM calculates the actual timing based on the signals from the CKP sensor and NE sensor.

25/52 TCV Duty Cycle % Indicates signal (duty ratio) to

drive the timing control valve. ECM changes the valve opening or closing travel according to the changes of the signal voltage (duty ratio) to adjust the proper injection timing.

If the value is out of the standard range, any fault is in the timing control valve, sensors or circuit or ECM. Check the valves, sensors, circuits and ECM.

If the value is out of the standard range, any fault is in the timing control valve, sensors or circuits or ECM. Check the valves, sensors, circuits and ECM.

If the value is out of the standard range, any fault is in the timing control valve, sensors or circuit or ECM. Check the valves, sensors, circuits and ECM.

Page 65

Engine Control System 1A-63

Item Tech 2 Data Display Unit Description How to use parameters

26/52 Cylinder 1 Compensation °CA Indicates adjustment of fuel

injection timing for each cylinder. As there are micro var iations in mechanical parts such as injectors, pumps and fuel pipes, the ECM makes correction based on various timing and respective sensor signals to stabilize the engine speed.

27/52 Cylinder 2 Compensation °CA Indicates adjustment of fuel

28/52 Cylinder 3 Compensation °CA Indicates adjustment of fuel

If the value is out of the standard range, any fault is in the injector, pump, various piping systems, sensors, or circuits or ECM. Check the engine mechanical parts, valves, sensors, circuits and ECM.

29/52 Cylinder 4 Compensation °CA Indicates adjustment of fuel

30/52 EGR Duty Cycle % Indicates signal (duty ratio) to

drive the motor to operate the EGR valve. ECM changes the valve opening or closing travel according to the changes of the signal voltage (duty ratio) to adjust the proper ECM operation.

If the value is out of the standard range, any fault is in the EGR valve, sensors, or circuits or ECM. Check the valves, sensors, circuits and ECM.

Page 66

1A-64 Engine Control System

Item Tech 2 Data Display Unit Description How to use parameters

31/52 Starter Switch On/Off Indicates the key switch is set

to the [S] position [ON] is indicated while the starter motor is running.

32/52 Neutral Switch On/Off Indicates the neutral switch

condition. [ON] is indicated while the neutral switch is ON.

33/52 Diagnostic Switch On/Off Indicates the diagnostic switch

(when pins of DLC are connected). Indication is turned [ON] when the pins of DLC are connected.

34/52 Key Switch On/Off Indicates the indication when

the key switch is set to the [ON] position. When the key switch position is [ON], the indication is [ON].

35/52 Idle Position Switch On/Off Indicates the signal value of the

switch installed to the accelerator pedal. Monitors the pedal position mutually with the accelerator pedal position sensor. At idling, the indication is turned [ON].

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

If the indication does not change, any fault is in the switch, circuit or ECM. Check the DLC, circuit and ECM in such a case.

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

36/52 AC Switch On/Off Indicates the condition of the

air conditioning switch. When the air conditioning switch is turned [ON], the indication becomes [ON].

37/52 Clutch Switch On/Off Indicates the clutch switch

condition. When the clutch switch is turned [ON], the indication becomes [ON].

38/52 Exhaust Brake Switch On/Off Indicates the condition of the

exhaust brake switch. When the exhaust brake switch is turned [ON], the indication becomes [ON].

39/52 Exhaust Brake (AT) Cutoff

Switch

On/Off On a vehicle equipped w ith an

automatic transmission, when the engine coolant t emperature is low, the exhaust brake is controlled and operated. Condition at this time is indicated. The indication is usually [OFF].

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

If the value does not change, poor communication with the AT control unit, system failure of AT, f aulty ECM or AT control unit, or fault in the exhaust brake or circuit is the cause. Check them in such a case.

Page 67

Engine Control System 1A-65

Item Tech 2 Data Display Unit Description How to use parameters

40/52 Exhaust Brake (ASR)

Cutoff Switch

41/52 PTO Switch On/Off Indicates the condition of PTO

42/52 Idle Speed Control On/Off I nd icates the engine idling

43/52 Engine Stop Switch On/Off Indicates the engine stop

On/Off On the vehicle equipped with

ASR, when the ASR operates, it controls the exhaust brake and stops it. Condition at this time is indicated. Us ually [O FF is indicated, which is changed to [ON] when ASR is operated.

switch. When the PTO switch is turned [ON], t he indication is turned [ON].

condition. When ECM judges the engine idling, the indication is turned [ON].

condition. When ECM determines engine stop, the indication is turned [ON].

If the value does not change, improper communication with ABS/ASR control unit, system failure of ABS or ASR, faulty ECM or ABS/ASR control unit, or fault in the circuit is the cause. Check them in such a case.

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

When the indication does not change, some fault is in the various sensors (rotating sensor system), idle position switch, circuit or ECM. Check the sensor, switch, circuit, and ECM.

If the indication does not change, any fault is in the motor unit, circuit or ECM. Check the motor unit, circuit and ECM in such a case.

44/52 Engine Start On/Off Indicates the starter motor

operating condition. While the starter motor is operating, the indication is [ON].

45/52 Accelerator Switch On/Off ECM uses it to know the

“Accelerator pedal opening condition” for various controls such as a starting control. When the accelerator pedal opening exceeds 50%, the indication is turned [ON].

46/52 Fuel Inj. Amount Limit

(Injection)

47/52 TCV Feedback On/Off When the engine starts

On/Off Indicates limit of fuel injection.

When the fuel injection is restricted by the failsafe function due to failure, etc., the indication is turned [ON].

rotating, TCV starts operating. ECM monitors the operation of TCV based on the signal from TCV and [ON] is indicated while the signal is being sent from TCV.

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

If the indication does not change according to the accelerator pedal stepping travel, some fault is in the sensor, circuit, throttle valve or ECM. Check the sensor, circuit, accelerator pedal or ECM in such a case.

If the indication turns to [ON], failure has occurred in some unit. Check DTC or oth er units and repair.

If the indication does not change, some fault is in the timing control valve, se nsors or circuits or ECM. Check the valves, sensors, circuits and ECM in such a case.

Page 68

1A-66 Engine Control System

Item Tech 2 Data Display Unit Description How to use parameters

48/52 Thermo Switch On/Off Indicates the condition of the

thermo switch which operates QWS. When the coolant temperature is low, the thermo switch is turned [ON] and operates QWS.

49/52 Exhaust Press. Valve 1 On/Off Indicates the condition of VSV

which operates the exhaust brake. When VSV starts operation, the indication is turned [ON].

50/52 Glow Time Lamp On/Off Indicates operating condition of

glow (QOS) lamp. When the lamp illumina tes, the indication is turned [ON].

51/52 Glow Time Relay On/Off Indicates operating condition of

the glow (QOS) relay. When the relay starts operation, the indication is turned [ON].

52/52 Starting Counter —

(Counts)

Frequency of signals given to the starter switch [S] is counted and indicated.

If the indication does not change, any fault is in the switch, circuit or ECM. Check the switch, circuit and ECM in such a case.

If the indication does not change, any fault is in the switch, VSV, circuit or ECM. Check the switch, VSV, circuit and ECM in such a case.

If the indication does not change, any fault is in the lamp, circuit or ECM. Check the lamp, circuit an d ECM i n such a case.

If the indication does not change, any fault is in the relay , circuit or ECM. Check the relay, circuit and ECM in such a case.

Check the frequency at the time of maintenance of the idling stop system.

(The display menu of Tech 2 may vary depending on the version of th e Tech 2 software or may be subj ec ted to modification without notice.)

Page 69

Diagnostic Chart

Engine Control System 1A-67

DTC

11 No Signal

13 Timing

Sensor actuator

(detection item)

Crank Position Sensor (CKP Sensor)

Control V alve (TCV) Fault

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

Judgment

criterion

CHECK ENGINE

lamp ON

Exhaust brake

lamp blinki ng

ON — When not CKP

signal is detected during 4 continuous broken tooth judgment at the idle speed.

ON — When the

injection timing feedback is controlled, after complete warm-up, absolute value of difference between the target TCV advance and actual TCV advance is more than 7°CA continuously for more than 20 seconds.

Failsafe Major fault Point inspected

Prohibition of feedback control. Prohibition of warm-up system, EGR, intake air throttling. Restricts the output.

Prohibition of warm-up system, EGR, intake air throttling. Restricts the output.

Large knocking sound, poor driveability.

Wire harness and connector (CKP signal system), crank position sensor, ECM.

Wire harness and connector (TCV system), timing control valve, ECM, fuel filter, fuel, injection pump.

14 Pump ROM

Fault

ON — Fault of

communication with pump ROM.

Corrects using data in EEPROM until communication is completed. Then there is no data, no correction is made until completion of initial communication. Restricts the output.

Large knocking sound, poor driveability.

Wire harness and connector (pump ROM system), pump ROM, ECM.

Page 70

1A-68 Engine Control System

DTC

Sensor actuator

(detection item)

15 Pu mp Cam

Sensor (NE Sensor) Short Break Fault

16 No Signal

(Open Wiring) From Pump Cam Sensor (NE Sensor)

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

Judgment

criterion

CHECK ENGINE

lamp ON

Exhaust brake

lamp blinking

— — When the

engine speed is more than 650rpm, pump cam sensor (NE) signal fault is detected more then 10 times.

ON — No NE pulse is

entered at idle speed in other than starting state. Or, after the starter switch turned ON, no NE pulse is entered and the ECM input voltage becomes below 22V even once, and when the starter switch turned OFF, the ECM input voltage exceeds 22V even once.

Failsafe Major fault Point inspected

Engine stall Wire harness

and connector (NE signal system), NE sensor, ECM.

Spill valve relay OFF, Timing control valve ON/OFF, Fixes the time.

Engine stall, Cannot start.

Wire harness and connector (NE system), NE sensor, ECM.

21 Engine

Coolant Temperature Sensor (ECT Sensor) Fault

23 Intake Air

Temperature Sensor (IAT Sensor) Fault

ON — When engine

coolant temperature sensor output voltage more than 4.9V continues.

ON — When intake

air temperature sensor output voltage below

0.05V or voltage over

4.95V continues.

Controls using set value of coolant temperature (starter sw i tc h ON: 20°C, starter switch OFF: 110°C) Warm-up system, EGR.

Controls using the set value of intake air temperature (25°C). Idle stop prohibited.

Faulty starting in cold state, poor driveability.

Poor driveability

Wire harness and connector (coolant temperature sensor system), coolant temperature sensor, ECM.

Wire harness and connector (intake air temperature sensor system), intake air temperature sensor, ECM.

Page 71

Engine Control System 1A-69

DTC

Sensor actuator

(detection item)

24 Accelerator

Position Sensor (AP) High Voltage, Low Voltage

25 No Signal

from Vehicle Speed Sensor (VS Sensor)

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

Judgment

criterion

CHECK ENGINE

lamp ON

Exhaust brake

lamp blinking

ON ON When

accelerator position sensor output voltage below 0.1V or over 4.85V continues.

ON — When the

clutch and gear are connected (normal clutch switch, neutral sensor) and engine speed is over 2200rpm, vehicle speed is 0 km/h for more than 5 seconds.

Failsafe Major fault Point inspected

Prohibits the exhaust brake, warm-up system, EGR, intake air throttling, controls the

Poor driveability

Wire harness and connector (AP signal system), accelerator position

sensor, ECM. accelerator opening to restrict the output, and fix to 0% or 30% (idle position switch fixed to OFF : 30%, idle position switch ON: 0%).

Warm-up system prohibited

Improper speedometer indication

Wire harness

and connector

(vehicle speed

sensor

system),

vehicle speed

sensor, ECM.

31 Idle Up

Volume Fault

32 Intake Air

Pressure Sensor (MAP Sensor) Fault

— — When idle up

volume output voltage below

0.2V or above

4.8V continues.

ON — When intake

air pressure signal voltage over 4.9V or below 0.1V detected for more than 3 seconds.

Idle up control prohibited

ECM continues control using the set value of 100kPa.

Poor driveability

Wire harness

and connector

(idle up volume

signal system),

idle up volume,

ECM.

Intake air

pressure

sensor, intake

air sensor

circuit, ECM.

Page 72

1A-70 Engine Control System

DTC

Sensor actuator

34 Exhaust

Brake Open Wiring Fault

35 Neutral

Switch (P/N Switch) Fault

36 Clutch

Switch Fault

(detection item)

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

Judgment

criterion

CHECK ENGINE

lamp ON

Exhaust brake

lamp blinking

ON ON When ECM

input voltage is over 16V, exhaust brake VSV is ON at idle speed, when VSV signal voltage is LOW or VSV is OFF, or when VSV signal voltage at HI continues.

ON ON If the neutral

switch is not changed from ON to OFF when the engine is rotating more than 60 seconds and the vehicle speed is over 80 km/h.

ON ON If the clutch

switch is not changed from ON or OFF, or from OFF to ON when the engine is rotating for more than 180 seconds after the engine starts (M/T vehicle).

Failsafe Major fault Point inspected

Prohibits the exhaust brake

Poor driveability

Exhaust brake

VSV circuit,

exhaust brake

VSV, main

relay, ECM.

Prohibits the exhaust brake and warm-up system.

Poor driveability

Neutral switch,

HSA,

instrument

panel, vehicle

speed sensor,

ECM.

Prohibits exhaust brake and warm-up system.

Poor driveability

Clutch switch,

HSA,

instrument

panel, vehicle

speed sensor,

ECM.

41 Fuel

Temperature Sensor (F T Sensor) Circuit High Voltage

ON — When output

voltage of fuel temperature sensor over

4.9V continues.

Controls using the fuel temperature set value (40°C). Idle stop prohibited.

Poor driveability

Wire harness

and connector

(fuel

temperature

sensor

system), fuel

temperature

sensor, ECM.

Page 73

Engine Control System 1A-71

DTC

Sensor actuator

(detection item)

51 Atmospheric Pressure

Sensor Fault

CHECK ENGINE

lamp ON

Exhaust brake

ON — When output

Judgment

criterion

lamp blinking

voltage of atmospheric pressure sensor under

1.9V or over

4.7V continues.

52 ECM CPU Fault — — When the ECM

input voltage is over 22V and starter switch is OFF at the initial stage.

Failsafe Major fault Point inspected

Controls using the

Poor driveability

Replace the

ECM. atmospheric pressure set value (100 kPa). Idle stop prohibited.

Restricts the limit accelerator

Engine stall ECM, non

OEM parts,

etc. opening to below specified value and returns the limit value gradually. Restricts the output. Idle stop prohibited.

ECM CPU Fault (Diagnosis with SUBCPU in E CU)

— ECM High Integrated IC

Fault

53 Engine

Driver Unit (EDU) Fault

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

— — When

EEPROM judges ECM fault.

ON — When pulse

signal fault continues in ECU with the starter switch OFF, ECM input voltage over 22V (faulty EEPROM ).

ON — When ECU

fault and open wiring of SPV continues more than 5 times.

SPV relay/glow relay OFF. Prohibits injection command on EDU. Exhaust brake ON. Idle stop prohibited.

Restricts the output. Idle stop prohibited.

SPV and SPV relay OFF. Prohibition of injection command to EDU and feedback control. Exhaust brake ON, Idle stop prohibited.

Engine stall ECM

Poor

ECM

driveability

Engine stall ECM, EDU,

spill valve

(SPV), spill

valve relay.

Page 74

1A-72 Engine Control System

DTC

Sensor actuator

(detection item)

55 Pu mp Unma tch

(Difference from ECM Specifications)

65 Idle Position

Switch Fault

Connector not Connected, Harness Open Wiring or Short, Failed Main Unit

Judgment

criterion

CHECK ENGINE

lamp ON

Exhaust brake

lamp blinking

ON — When pump

ROM does not conform with ECM (normal pump ROM)

ON ON Idle position

switch OFF when the accelerator position sensor output voltage is under 0.6V, or idle position switch is ON when the accelerator position sensor output voltage is over 1.0V for more than 10 seconds but the accelerator position sensor is normal. Or when the sensor output voltage is out of the specified value range: < AP sensor adjustment reference voltage>

• Idle point:

0.43 ~ 0.73V

• WOT point:

4.10 ~ 4.70V

• Input voltage: 5V (idle position switch operating voltage: 0.59 ~

0.79V).

Failsafe Major fault Point inspected

Restricts the output. Idle stop

Cannot start ECM (injection

pump

identification). prohibited.

Restricts the output.

Poor driveability

Idle position

switch, ECM. Prohibits the exhaust brake and warm-up system. Idle stop prohibited.

Page 75

DTC11 - No Signal CKP Sensor

Engine Control System 1A-73

1.25 B/L

CKP

ROM

0.5

G/B

G/R

Engine Control Module (ECM)

Compensation ROM and NE Sensor are built in the Injection Pump

Sensor

0.5 W

B5 (+)

0.5 R

B11

()

Sensor

0.5 G

B6 (+)

B12

()

0.5 L

D13D3D17

Circuit Description

CKP (crank position) sens or generates CKP reference signal. While the crank shaft rotates once, a CKP reference pulse is generated. ECM calculates the engine speed and crankshaft position using the CKP reference signal. DTC 11 is set when ECM receives no pulse on the CKP reference circuit.

Major Faulty Event

• Large knocking sound

• Poor driveability

Conditions for Setting the DTC

• While broken tooth judgment is carried out 4 continuous times at th e idle speed, not any CKP signal is detected.

LNW21ALF000701-X

Action Taken when the DTC Sets

• ECM illuminates th e CHECK ENGINE La mp (MIL) when DTC is set.

• Advance feedback control prohibited

• Warm-up system prohibited

• EGR prohibited

• Intake air throttle prohibited

• Output restricted

Conditions for Clearing MIL/DTC

When the system fails and the DTC is stored to the ECM, even repairing the fau lty portio n will not cle ar the DTC from the memory. To clear the DTC, conduct the following steps.

• Keep the starter switch turned on and the engine is not running.

• Short the data link connector.

Page 76

1A-74 Engine Control System

Perform the following steps.

1. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

2. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

3. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

4. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

5. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

Step Action Value(s) Yes No

Perform the "On-Board Diagnostic (OBD)

System Check.?

1. Review and record the failure records information.

2. Clear DTC 11.

3. Start the engine and idling for 1 minute.

4. Observe DTC.

Was DTC 11 set up? Check the CKP sensor is correctly installed. If

a problem, repair as necessary.

Was a problem detected? Starter switch "OFF". Disconnect the ECM

connector and measure the resistance value

between CKP+ and CKP–.

6. After the above operations are properly completed, the Check Engine Lamp (MIL) illuminates for 3 seconds to report the memory is cleared.

7. Turn off the key switch. Wait for 5 seconds and turn on the starter switch again.

When Tech 2 ha s been connected to the vehicle, the DTC can be cleared through the memory clear operation with Tech 2.

Diagnostic Aids

An intermittent may be cause by a poor connection, rubbed-through wire in sulation, or a wi re broken ins ide the insulation. Check for the following conditions.

• Poor connection: Inspect the ECM harness and connector for improper mating, broken locks, improperly formed or damaged pin, and pin-to-wire connection

• Damaged harness: Ch eck the wiring harness for damage.

—

25Ω

Go to Step 2

Go to Step 3

Verify repair Go to Step 4

Go to "OBD

System Check"

"Diagnostic Aids"

Refer to

Is the value normal? Remove the CKP sensor connector. Measure

the resistance value between pins of the

sensor. Is the value normal?

Repair the open wiring or poor connection of between ECM and CKP.

Is the repair complete? Replace the CKP sensor.

Is the action complete? Check the CKP s ensor circuit for +B short or

ground short. If a problem, repair as

necessary. Was a problem?

Go to Step 8 Go to Step 5

25Ω

Go to Step 6 Go to Step 7

—

Verify repair —

—

Verify repair —

—

Verify repair Go to Step 9

Page 77

Engine Control System 1A-75

Step Action Value(s) Yes No

Remove the CKP sensor. Turn the crankshaft, and check from the CKP sensor installing hole f or damage of the poi nter. If a

problem, repair as necessary.

—

Was a problem? Check the ECM connecter pin for fault.

If a problem, repair as necessary.

Was a problem? Replace the ECM.

Is the action complete?

DTC13 - TCV Fault

1.25

Main Relay

W/R

EXH Brake Magnetic Valve

SP Valve Relay

Verify repair Go to Step 10

—

Verify repair Go to Step 11

—

Verify repair —

EDU

High Voltage

Generating Circuit

SPV+

TCV

1.25 Y/R

D12

0.5 G/R

D10 D16 D20

0.5 L/R

Engine Control Module (ECM)

0.5 G/W

Control

Circuit

EDU

C A B

SPV

GND (Case)

D E F

LNW21ALF000801-X

SPV

Page 78

1A-76 Engine Control System

Circuit Description

Timing control valve (TCV) is installed to the injection pump. Electric signal fr om ECM opens or closes the fuel passage between the high pressure chamber and low pressure chamber of the timer piston. When current flows to the coil, the stator core becomes an electromagnet, which co ntracts the spring, the m oving core is absorbed and the fuel passage is opened. ECM controls the TCV (duty control) and controls the fuel injection start timing. DTC 13 is set up when the target advance is remarkably different from the actual advance.

Major Faulty Event

• Large knocking sound

• Poor driveability

Conditions for Setting the DTC

• At the injection timing feedback, after complete warm-up, absolute value of difference more than 7°CA between the target TCV advance an d actual TCV advance has continued for more than 20 seconds.

6. After the above operations are properly completed, the Check Engine Lamp (MIL) illuminates for 3 seconds to report the memory is cleared.

7. Turn off the key switch. Wait for 5 seconds and turn on the starter switch again.

When Tech 2 ha s been connected to the vehicle, the DTC can be cleared through the memory clear operation with Tech 2.

Diagnostic Aids

Check for the following conditions.

• Poor connection at the ECM: Inspect harness connectors for bac ked-out pins, improp er mating, broken locks, imprope rly formed or dama ged pins, and poor pin-to-wire connection.

• Damaged harness: Ch eck the wiring harness for damage.

Action Taken when the DTC Sets

• When any failure is detected first time, ECM illuminates the CHECK ENGINE Lamp (MIL).

• Warm-up system, EGR and intake a ir throttle are prohibited.

• Output is restricted.

Condition for Clearing the MIL/DTC

When the system fails and the DTC is stored to the ECM, even repairing the faulty po rtion will not clea r the DTC from the memory. To clear the DTC, conduct the following steps.

• Keep the starter switch turned on and the engine is not running.

• Short the data link connector.

Perform the following steps.

1. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

2. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

3. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

4. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

5. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

Page 79

Engine Control System 1A-77

Step Action Value(s) Yes No

Perform the "On-Board Diagnostic (OBD)

System Check.?

1. Review and record the failure records information.

2. Clear DTC 13.

3. Start the engine, and run the idling until

the coolant temperature increases above 60°C.

4. Observe the DTC.

Set the DTC 13?

1. Starter switch “OFF”.

2. Disconnect the TCV.

3. Check for open wiring or ground short between TCV connector and ECM harness connector a nd between the TCV connector and power source.

4. If a problem is detected, repair as necessary.

—

Go to Step 2

Go to Step 3

Go to "OBD

System Check"

Refer to

"Diagnostic Aids"

Was a problem detected? Check the connecti on at T CV a nd repla ce the

pin as necessary.

Was replacement of pin required? Check the connection at ECM and replace the

pin if required.

Was the replacement of the pin required? Measure the resistance value between the

TCV connecter pins

Is the value normal? Check the timing gear installing condition.

If a problem is detected, repair as necessary.

Was a problem detected? Replace the injection pump

Was DTC 13 set up after the step? Replace the ECM.

Is the action complete?

Verify repair Go to Step 4

—

Verify repair Go to Step 5

—

Verify repair Go to Step 6

45Ω

Go to Step 7 Go to Step 8

—

Verify repair Go to Step 9

—

Verify repair Go to Step 9

—

Verify repair —

Page 80

1A-78 Engine Control System DTC14 - Pump ROM Fault

1.25 B/L

CKP

ROM

0.5

G/B

G/R

Engine Control Module (ECM)

Compensation ROM and NE Sensor are built in the Injection Pump

Sensor

0.5 W

B5 (+)

0.5 R

B11

()

Sensor

0.5 G

B6 (+)

B12

()

0.5 L

D13D3D17

Circuit Description

Pump ROM corrects discrepancy of injection amount and injection timing caused by discrepancy of correlation between the NE (pump cam) signal and injection wavefo rm, precisely for each injection p ump. NE signal is detected by the NE sensor and used to control the injection amount, injection timing and idle speed. ECM controls the inj ection amou nt and injecti on timing based on the signal from th e pump ROM, CKP sens or and NE sensor. DTC 14 is set up when communication fault is caused with the pump ROM.

Major Faulty Event

• Poor driveability

LNW21ALF000701-X

Conditions for Setting the DTC

• When Fault is caused in the communication with the pump ROM when data is being received.

Action Taken when the DTC Sets

• When DTC is set, ECM illuminates the CHECK ENGINE Lamp (MIL).

• ECM continues control using the set value.

• Output is restricted.

Conditions for Clearing MIL/DTC

When the system fails and the DTC is stored to the ECM, even repairing the fau lty portio n will not cle ar the DTC from the memory. To clear the DTC, conduct the following steps.

• Keep the starter switch turned on and the engine is not running.

Page 81

Engine Control System 1A-79

• Short the data link connector.

Perform the following steps.

1. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

2. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

3. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

4. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

5. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

6. After the above operations are properly completed,

Step Action Value(s) Yes No

Perform the "On-Board Diagnostic (OBD)

System Check.?

1. Review and record the failure records information.

2. Clear DTC 14.

3. Start the engine, an d run the idling for 5

minutes.

4. Observe the DTC.

Set the DTC 14?

1. Starter switch "OFF".

2. Disconnect the pump ROM.

3. Check the pump ROM circuit between the pump ROM connecto r and ECM harnes s connector for open wiring or ground short.

4. Check for open wiring between the pump ROM connector and ground.

5. If a problem is detected, repair as necessary.

the Check Engine Lamp (MIL) illuminates for 3 seconds to report the memory is cleared.

7. Turn off the key switch. Wait for 5 seconds and turn on the starter switch again.

When Tech 2 ha s been connected to the vehicle, the DTC can be cleared through the memory clear operation with Tech 2.

Diagnostic Aids

An intermittent may because by a poor connection, rubbed-through wire in sulation, or a wi re broken ins ide the insulation. Check for the following conditions.

• Poor connection: Inspect the ECM harness and connector for improper mating, broken locks, improperly formed or damaged pin, and pin-to-wire connection

• Damaged harness: Ch eck the wiring harness for damage.

—

Go to Step 2

Go to Step 3

Go to "OBD

System Check"

"Diagnostic Aids"

Refer to

Was a problem detected? Check the connection at the pu mp ROM and

replace the pin as necessary.

Was the replacement of the pin required? Check the connection at ECM and replace the

pin as necessary.

Was replacement of the pin required? Replace the injection pump.

Set the DTC14 after completion of the step? Replace the ECM.

Is the action complete?

Verify repair Go to Step 4

—

Verify repair Go to Step 5

—

Verify repair Go to Step 6

—

Verify repair Go to Step 7

—

Verify repair —

Page 82

1A-80 Engine Control System DTC15 - Pump Cam Sensor (NE Sensor) Short Break Fault

1.25 B/L

CKP

ROM

0.5

G/B

G/R

Engine Control Module (ECM)

Compensation ROM and NE Sensor are built in the Injection Pump

Sensor

0.5 W

B5 (+)

0.5 R

B11

()

Sensor

0.5 G

B6 (+)

B12

()

0.5 L

D13D3D17

Circuit Description

The NE (pump cam) sensor generates NE signal. ECM determines the injection amount and injection timing using the NE signal and starts the fuel injection. DTC 15 is set up when the number of pulses on the NE standard circuit received by ECM is not proper.

Major Fault Event

• Engine stall

Conditions for Setting the DTC

NE signal Fault arose m ore than 10 times dete ct when the engine speed is more than 650rpm.

Action Taken when the DTC Sets

• If any failure is detected, the CHECK ENGINE Lamp (MIL) is kept ON (not blinking). (DTC is checked by Tech 2 or diagnosis switch.)

LNW21ALF000701-X

Conditions for Clearing MIL/DTC

When the system fails and the DTC is stored to the ECM, even repairing the fau lty portio n will not cle ar the DTC from the memory. To clear the DTC, conduct the following steps.

• Keep the starter switch turned on and the engine is not running.

• Short the data link connector.

Perform the following steps.

1. Turn off the idle position swi tch for not le ss than 1 second but not more than 3 seconds. (Press the accelerator pedal.)

2. Turn on the idle position switch for not less than 1 second but not more than 3 seconds. (Release the accelerator pedal.)

3. Turn off the idle position swi tch for not le ss than 1 second but not more than 3 seconds. (Press the accelerator pedal.)

Page 83

Engine Control System 1A-81

4. Turn on the idle position switch fo r not less th an 1 second but not more than 3 seconds. (Release the accelerator pedal.)

5. Turn off the idl e position switch for n ot less than 1 second but n ot more than 3 seconds. (Pr ess the accelerator pedal.)

6. After the above operations are properly completed, the Check Engine Lamp (MIL) illuminates for 3 seconds to report the memory is cleared.

7. Turn off the key switch. Wait for 5 seconds and turn on the starter switch again.

When Tech 2 h as been connected to the vehicle, the DTC can be cleared through the memory clear operation with Tech 2.

Step Action Value(s) Yes No

Perform the "On-Board Diagnostic (OBD)

System Check.?

1. Review and record the failure records information.

2. Clear DTC 15.

3. Start the engine and running within the

safety range.

4. Observe the DTC.

Set the DTC 15?

1. Starter switch "OFF".

2. Disconnect the NE sensor.

3. Check for open wiring, ground short or +B short between the NE censor connector and ECM connector.

4. If a problem is detected, repair as necessary.

Diagnostic Aids

An intermittent may be cause by a poor connection, rubbed-through wire in sulation, or a wi re broken ins ide the insulation. Check for the following conditions.

• Poor connection: Inspect the ECM harness and connector for improper mating, broken locks, improperly formed or damaged pin, and pin-to-wire connection

• Damaged harness: Ch eck the wiring harness for damage.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Chart.

2. Check for the presence of failure.

—

Go to Step 2

Go to Step 3

Go to "OBD

System Check"

"Diagnostic Aids"

Refer to

Was a problem detected? Check the connection at the pu mp ROM and

replace the pin as necessary.

Was the replacement of the pin required? Check the connection at ECM and replace the

pin as necessary.

Was replacement required? Replace the injection pump.

Set the DTC15 after completion of the step? Replace the ECM.

Is the action complete?

Verify repair Go to Step 4

—

Verify repair Go to Step 5

—

Verify repair Go to Step 6

—

Verify repair Go to Step 7

—

Verify repair —

Page 84

1A-82 Engine Control System DTC16 - No Signal from Pump Cam Sensor (NE Sensor)

1.25 B/L

CKP

ROM

0.5

G/B

G/R

Engine Control Module (ECM)

Compensation ROM and NE Sensor are built in the Injection Pump

Sensor

0.5 W

B5 (+)

0.5 R

B11

()

Sensor

0.5 G

B6 (+)

B12

()

0.5 L

D13D3D17

Circuit Description

The NE (pump cam) sensor generates NE signal. ECM determines the injection amount and injection timing using the NE signal and starts the fuel injection. DTC 16 is set up when ECM does not receive NE signal.

Major Faulty Conditions Fault Condition

• Engine stall

• Engine cannot start.

Conditions for Setting the DTC

• NE signal is not rece ived at the idle spe ed, excep t for the starting.

• When all of the following conditions are met:

1. When the starter switch is turned ON, no NE signal is received.

LNW21ALF000701-X

2. When the starter swit ch is turned ON, ECM input voltage decreases below 22V even once.

3. When the starter switch i s turned OFF, ECM input voltage increases over 22V even once.

Action Taken when DTC Sets

• When DTC is set, ECM illuminates the CHECK ENGINE Lamp (MIL).

• Injection signal is stopped.

• Spill valve relay is turned OFF.

• Timing control valve ON/OFF time is fixed.

Conditions for Clearing MIL/DTC

When the system fails and the DTC is stored to the ECM, even repairing the fau lty portio n will not cle ar the DTC from the memory. To clear the DTC, conduct the following steps.

Page 85

Engine Control System 1A-83