ISUZU 4HK-1 Service Manual

FOR SERVICE TRAINING

4HK1-TC ENGINE

-Engine Mechanical Features-

-Engine Control System & Diagnosis-

Applicable Model

	Model Year	Vehicle Model	Main Market
	2005	NPR & NQR	General Export (Euro 3 Regulation)
			Europe, Australia, Thailand, South Africa & etc.

ISUZU MOTORS LIMITED

N*R 4HK1-TC Engine-1

INTRODUCTION & ENGINE MECHANICAL FEATURES

The 2005 model year NPR/NQR truck, the 4HK1-TC inline 4 cylinder engine replaces the 4HE1-TC engine for advanced exhaust emission countries. The 4HK1-TC engine has been newly developed on the basis of previous 4HE1-TC engine, with additional features including the employment of four valve mechanism per a cylinder that are operated via a single camshaft, common rail fuel injection system, water-cooled exhaust gas re-circulation (EGR) system, and the change of combustion chamber form. The larger engine displacement and the common rail fuel injection system have resulted in an increase both in maximum output and torque, and met Euro 3 emission regulation standard. Most conspicuous items are listed below.

Multi fuel injection type high-pressure common rail system and is made with Denso.

Single overhead camshaft (OHC) with 4 valves per a cylinder.

Electrical control EGR valve, water-cooled EGR cooler.

Turbocharger with intercooler.

Engine Type	Maximum Output	Maximum Toruque
4HK1-TCS	129kw (175ps)/2600RPM	500Nm (51kgm)/1500-2000RPM
4HK1-TCN	110kw (150ps)/2600RPM	404Nm (41kgm)/1500-2600RPM

The base transmission is MYY for 4HK1-TCN low output engine, MZZ for 4HK1-TCS high output engine. The Smoother system is available for only MYY transmission.

			N*R 4HK1-TC Engine-2
			Major mechanical changed items are listed below.
Part	Status		Description or Reason in Comparison with 4HE1-TC Engine
Cylinder Block	Change		Bore size is upped (110mm to 115mm / 4.33in to 4.53in)
Crankshaft	Carry-over		-
Cylinder Head	Change		Four valve type with camshaft position sensor hole
Cylinder Head Gasket	Change		Cylinder head is changed
Camshaft	Change		Four valve type is employed
Camshaft Gear	Change		Scissors gear type is employed
Inlet Valve	Change		Four valve type is employed
Exhaust Valve	Change		Four valve type is employed
Valve Spring	Change		Four valve type is employed
Rocker Arm	Change		Four valve type is employed
Cylinder Head Cover	Change		Four valve type is employed
Timing Gear Train	Change		Fuel system is changed
Flywheel	Change		Crankshaft position sensor is ring added
Flex Plate	Carry-over	-
Flywheel Housing	Change		Common rail system is employed & crankshaft position sensor
			hole
Engine Hanger	Change		Cylinder head and EGR layout is changed
Piston	Change		Bore size is upped
Piston Ring	Change		Bore size is upped
Connecting Rod	Carry-over	-
Oil Pan	Change		Oil level switch is added
Oil Pump	Carry-over	-
Oil Cooler	Change		Engine size is changed
Front Cover	Carry-over	-
Water Pump	Carry-over	-
Cooling Fan	Change (4HK1-TCS)		4HK1-TCS: Size is changed to improve performance
	Carry-over (4HK1-TCN)
EGR Cooler	New		Newly adopted
EGR Pipe	Change		EGR layout is changed
EGR Valve	Change		Electrical control type
PCV System	Carry-over	-
Fuel Pump	Change		Common rail system is employed (supply pump)
Injection Nozzle	Change		Common rail system is employed
Injection Pipe	Change		Common rail system is employed
Fuel Pipe	Change		Common rail system is employed
Intake Duct	Change		Layout is changed & boost pressure sensor are added
Intake Manifold	Change		Layout is changed
Intercooler	Change		Size is upped
Exhaust Manifold	Carry-over	-
Turbocharger	Change		Wastegate valve actuator setting is changed
ACG	Change
Starter	Carry-over	-
Engine Harness	Change		Common rail system is employed

		N*R 4HK1-TC Engine-3
ENGINE MAIN DATA & SPECIFICATIONS
Engine Model	4HE1-TC
Engine Type	Diesel, Four Cycle
Cylinder Layout - Number of Cylinders	Inline-Four Cylinders
Fuel Injection Order	1-3-4-2
Bore x Stroke (mm/in)	110.0 x 125.0 / 4.33 x 4.92	115.0 x 125.0 / 4.53 x 4.92
Total Displacement (cc)	4751	5193
Compression Ratio	18.0	18.5
Compression Pressure at 200 rpm (MPa / psi)	3.0 / 441	3.3 / 478
Combustion Camber Type	Direct Injection
Cylinder Liner	Dry Type
Idle Speed (rpm)	800±25	650±25
Fuel System	Mechanical Type Governor	Common Rail System
Injection Pump Type	BOSCH In-line Type (MITICS)	DENSO (HP3) Supply Pump
		Electrical Controlled Injector
Injection Nozzle Type	Hole Nozzle (Mechanical Type)
		(G2)
Number of Injection Hole	6	7
Diameter of Injection Hole (mm)	0.21	0.16
Injection Nozzle Operating Pressure (MPa)	17.65	Electrically Controlled
Fuel Filter Type	Cartridge Paper Element & Water Separator
Valve System
Valve Layout	Overhead Valve
Drive Type	Gear Drive
Intake Valve Open At BTDC (deg)	14.0	19.0
Intake Valve Close At ABDC (deg)	51.0	53.0
Exhaust Valve Open At BBDC (deg)	49.0	48.0
Exhaust Valve Close At ATDC (deg)	16.0	14.0
Intake Valve Clearance At Cold (mm)	0.4
Exhaust Valve Clearance At Cold (mm)	0.4
Cooling System
Cooling Method	Water Cooled
Water Capacity (litter/gal)	14 (3.7)
Water Pump Type	Centrifugal Impeller Type
Thermostat Type	Wax Pellet
Thermostat Opening Temperature (deg. C / deg. F)	82 & 85 / 180 & 185
Lubricating System
Lubricating Method	Full Flow Pressure Circulation

			N*R 4HK1-TC Engine-4
Oil Pump Type	Gear
Oil Capacity (litter/gal)	13 (3.4)
Oil Filter Type	Cartridge Paper Element
Air Cleaner Type	Dry Paper Element
EGR System	W/O Cooler & Vacuum Control		W/Cooler & Electrical Control
	EGR Valve		EGR Valve
PCV System	Open Type
Preheating System	Glow Plug
Starting System
Starter Motor Output (V-kW)	24 - 3.0
Charge System
Alternator Output (V-A)	24 – 50, 60 or 80
Regulator Type	IC
Battery Size	115E41R x 2

GEAR TRAIN

Valve Train

N*R 4HK1-TC Engine-5

To rotate the fuel supply pump with engine speed, idle gear has changed with three steps. The crankshaft gear (42 teeth) corresponds with the large diameter of idle gear A (72 teeth). The fuel supply pump gear (35 teeth) corresponds with the middle diameter of idle gear A (60 teeth). The idle gear B (61 teeth) corresponds with the small diameter of idle gear A (30 teeth).

1.Camshaft Gear (Z=35)

2.Idle Gear C (Z=41)

3.Idle Gear B (Z=61)

4.Idle Gear A (Large) (Z=72)

5.Idle Gear A (Middle) (Z=60)

6.Idle Gear A (Small) (Z=30)

7.Fuel Supply Pump Gear (Z=35)

8.Crankshaft Gear (Z=42)

To improve exhaust emission and engine output performance, four valve mechanism is newly adopted for 4HK1-TC engine. Note that the adjustment method of valve clearance has been changed from 4HK1-TC engine as following steps.

1.Rotate the crankshaft to make the No.1 cylinder meet the compression top dead center (TDC). There are 2 marks stamped on the crank pulley. The mark (1) is used to bring the engine No.1 or No. 4 cylinder to TDC. The mark (2) is irrelevant. Do not use the mark (2).

N*R 4HK1-TC Engine-6

Cylinder No.

1

2

3

4

Valve

IN

EX

IN

EX

IN

EX

IN

EX

No.1

Cylinder

O

O

O

O

Compression

TDC

No.4

Cylinder

X

X

X

X

Compression

TDC

2.Loosen fully each adjusting screw (8) & (2) of the bridge and the rocker arm.

3.Insert a 0.4mm (0.016in) thickness gauge between the tip of the rocker arm and bridge cap (5), and adjust the clearance with the adjusting screw (3) on the rocker arm, and then fix it with a lock nut (4).

4.With a thickness gauge kept inserted, check that the adjusting screw (6) contacts the valve shaft end and the movement of the thickness gauge has become tight when the adjusting screw (6) on the bridge is tightened lightly.

5.Check the valve shaft end on the opposite side floats or it contacts obliquely. In case of a floating or oblique contact, loosen a little the adjusting screw (6) on the bridge side and adjust so that the valve shaft ends on both sides get in contact properly. Bridge (8) & valve shaft end clearance less than 0.1 mm (0.004in).

6.After the adjustment so that the end of the valves on both sides touch properly, tighten up the lock nut (7) on the bridge (8).

Note that unless the bridge is kept horizontal, the bridge is pressed obliquely, thus causing the bridge and bridge guide to be seized or damaged. Therefore, exact adjustment is required.

Valve clearance: 0.4mm (0.016in) intake & exhaust side at cold

Adjusting screw lock nut tightening torque: 22Nm (16lb ft)

At the No.1 cylinder compression top dead center, the valves with “O” mark in the following table, or at the No.4 cylinder compression top dead center, the valve with “X“ mark can be adjusted.

N*R 4HK1-TC Engine-7

Fuel Supply Pump Installation

1. Apply white paint to the top of the fuel supply pump gear tooth directly above the stamped “O” mark.

2. Rotate the crankshaft to the compression top dead center (TDC). There are 2 marks stamped on the crank pulley. The mark (1) is used to bring the engine No.1 or No. 4 cylinder to TDC. The mark (2) is irrelevant. Do not use the mark (2).

3. Install the O-ring to the fuel supply pump.

4. Align a slit of the fuel supply pump bracket with a white paint on the gear and install the fuel supply pump in the gear case using the stud bolts as a guide.

N*R 4HK1-TC Engine-8

5. Check through the hole (1) that a white paint (2) on the gear is in the position shown on the left.

Fixing nut tightening torque: 50Nm (37lb ft) Fixing bolt tightening torque: 76Nm (56lb ft)

CYLINDER HEAD COVER & HEAD COVER CASE

Along with the employment of a common rail type fuel injection system, the head cover is split and housed in a newly introduced head cover case attached with an intermediate connector for the injector. The head cover case is so designed that it is secured individually to the cylinder head with four bolts, and further it is tightened together with the head cover with nine bolts. Accordingly, the head cover is removable individually regardless of the injector harness, thus enabling easy inspection and service including the valve clearance adjustment.

1. Gasket

2. Oil Filler Cap

3. Head Cover Bolt

4. Head Cover

5. Gasket

6. Head Cover Case

7. Intermediate Harness Connector

8. Cylinder Head Cover Case Bolt

9. Cylinder Head

10. Gasket

11. Connector Fixing Bolt

N*R 4HK1-TC Engine-9

ENGINE CONTROL MODULE (ECM)

The engine control module (ECM) is located at inside of engine-side cover on the left via mounting bracket and is beside the engine. The ECM is made by Transtron. The ECM mainly controls the following.

Fuel injection control

Fuel timing control

Exhaust gas recirculation (EGR) system control

Preheating system control

Exhaust brake control

Power take off (PTO) control

On-board diagnostics for engine control

The ECM constantly observes the information from various sensors. The ECM controls the systems that affect vehicle performance. The ECM performs the diagnostic function of the system. The ECM can recognize operational problems, alert the driver through the malfunction indicator lamp (MIL), and store diagnostic trouble code (DTC). DTC identify the system faults to aid the technician in making repair.

This diagnostic applies to internal microprocessor integrity conditions within the ECM. The electronically erasable programmable read only memory (EEPROM) memorize learning data and injector ID code data for engine control and communication with other control module.

Symbol “!” warns you of an electric shock hazard. To avoid shock and possible serious injury, DO NOT touch the terminals. When disconnecting the harness connector, always turn OFF the ignition switch or disconnect the battery cable.

Parts number of each ECM mainly differs with following contents.

Engine specification (output or torque) Transmission specification (MYY, MZZ or Smoother) Speed limiter application

Notice!

If the ECM is to be replaced the fuel injector ID Code Data (24, 0-9 or A-F characters for each fuel injector) MUST be programmed into the new ECM.

Notice!

This ECM does not have ability of re-flash function by Service Programming System (SPS) via Tech 2 scan tool.

N*R 4HK1-TC Engine-10

							N*R 4HK1-TC Engine-11
ECM Connector Pin Assignment
Pin No.	Pin Function		Pin	Pin Function		Pin	Pin Function
			No.			No.
1	ECM Power Ground		28	Not Used		55	Not Used
2	Main Relay Voltage		29	Not Used		56	Not Used
3	ECM Power Ground		30	Not Used		57	Not Used
4	ECM Power Ground		31	Not Used		58	Not Used
5	Main Relay Voltage		32	Not Used		59	Not Used
6	Malfunction Indicator Lamp (MIL)		33	Refrigerator Switch Input Signal		60	APP Sensor 2, BARO Sensor, IAT
	Control						Sensor Low Reference
7	Exhaust Brake Lamp Control		34	A/C Switch Input Signal		61	APP Sensor 2, BARO Sensor, IAT
							Sensor 5V Reference
8	Engine Speed Signal Output to		35	Not Used		62	ECM Signal Ground
	IPC
9	Not Used		36	Not Used		63	APP Sensor 1 Input Signal
10	Glow Plug Relay Control		37	CAN Low Signal		64	APP Sensor 2 Input Signal
11	Glow Indicator Lamp Control		38	Keyword 2000 Serial Data		65	Not Used
12	Not Used		39	APP Sensor 2 Shield		66	Idle Up Sensor Input Signal
13	Not Used		40	Main Relay Power Supply		67	Not Used
				APP Sensor 1, Idle Up Sensor,
14	Starter Cut Relay Control		41	Remote PTO Accelerator		68	Not Used
				Sensor Low Reference
				APP Sensor 1, Idle Up Sensor,
15	Exhaust Brake Solenoid Control		42	Remote PTO Accelerator		69	Not Used
				Sensor 5V Reference
16	Not Used		43	ECM Signal Ground		70	Remote PTO Accelerator Sensor
							Input Signal
17	Not Used		44	PTO Operation Switch Input		71	BARO Sensor Input Signal
				Signal
18	CAN High Signal		45	Exhaust Brake Switch Input		72	IAT Sensor Input Signal
				Signal
19	VSS Input Signal		46	Start Position Input Signal		73	Not Used
20	APP Sensor 1 Shield		47	Clutch Switch Input Signal (M/T		74	Not Used
				Only)
21	Main Relay Power Supply		48	Park Brake Switch Input Signal		75	Not Used
22	Not Used		49	Not Used		76	Not Used
23	Not Used		50	Neutral Switch Input Signal		77	Not Used
24	Ignition ON Switch Input Signal		51	Engine Warm Up Switch Input		78	Not Used
				Signal
25	Not Used		52	Diag Switch		79	Not Used
26	Not Used		53	Not Used		80	Not Used

							N*R 4HK1-TC Engine-12
27	Not Used		54	Not Used		81	ECM Case Ground
Pin No.	Pin Function		Pin	Pin Function		Pin	Pin Function
			No.			No.
82	FRP Sensor Input Signal		96	Not Used		110	Not Used
83	FT Sensor Input Signal		97	SCV Low Control		111	EGR Valve DC Motor Control
84	ECT Sensor Input Signal		98	CMP Sensor 12V Reference		112	Not Used
85	Not Used		99	CMP Sensor Input Signal		113	SCV High Control
86	EGR Valve Position Sensor Input		100	FRP Sensor, CMP Sensor		114	Not Used
	Signal			Shield
87	FRP Sensor, EGR Valve Position		101	FRP Sensor, EGR Valve		115	Not Used
	Sensor Input Signal			Position Sensor Low Reference
88	Not Used		102	Intake Throttle Solenoid Valve		116	Cylinder #2, #3 Injector Power
				Control			Supply
89	SCV Low Control		103	EGR Valve DC Motor Power		117	Cylinder #4 Injector Control
				Supply
90	FRP Sensor Input Signal		104	Not Used		118	Cylinder #2 Injector Control
91	Boost Pressure Sensor Input		105	SCV High Control		119	Cylinder #1 Injector Control
	Signal
92	Not Used		106	CKP Sensor Low Signal Input		120	Cylinder #3 Injector Control
93	Not Used		107	CKP Sensor High Signal Input		121	Cylinder #1, #4 Injector Power
							Supply
94	Not Used		108	Boost Pressure Sensor, CKP
				Sensor Shield
	Boost Pressure Sensor 5V			Boost Pressure Sensor, ECT
95			109	Sensor, FT Sensor Low
	Reference
				Reference

N*R 4HK1-TC Engine-13

ECM Inputs & Outputs

Sensor Input		Fuel Injection Control Output
•	Crankshaft position (CKP) sensor	•	Suction control valve (SCV)
•	Camshaft position (CMP) sensor	•	Fuel injector #1
•	Intake air temperature (IAT) sensor	•	Fuel injector #2
•	Engine coolant temperature (ECT) sensor	•	Fuel injector #3
•	Fuel temperature (FT) sensor	•	Fuel injector #4

•Fuel rail pressure (FRP) sensor

•Barometric pressure (BARO) sensor

•	Boost pressure sensor		Actuator Control Output
•	Accelerator pedal position (APP) sensor		•	Intake throttle solenoid valve
•	Vehicle speed sensor (VSS)		•	Exhaust brake solenoid valve
•	EGR valve position sensor		•	EGR valve motor
•	Idle up control sensor	EC
•	Remote PTO accelerator sensor	M
			Relay & Lamp Control Output
			•	Glow relay
Switch Input			•	Starter cut relay
			•	Malfunction indicator lamp (MIL)
•	Ignition switch (ON/start position)
			•	Glow indicator lamp
•	Clutch switch (M/T)
			• Exhaust brake indicator lamp
•	Park brake switch

•Park/Neutral switch

•Exhaust brake switch

•Engine warm up switch

•A/C switch

•	PTO switch	Communication
•	Refrigerator switch	•	Tech 2 (Keyword 2000)
•	Diag request switch	•	Controller area network (CAN)

N*R 4HK1-TC Engine-14

The ECM monitors the battery voltage through the ECM main relay load supply voltage terminals “2” and “5”, and the ignition voltage on the ignition voltage feed terminal “24” to make sure that the voltage stays within the proper range. When the charging system detects a malfunction, the charge indicator will light.

Related DTC

DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC
	Tool
P1625	ECM Main Relay	DTC P1603 is not set.	The ECM detects that a low
	Circuit	The ignition switch is ON.	voltage condition on the ECM
		The ignition switch ON time is	main relay voltage feed circuit for
		longer than 3 seconds.	longer than 3 seconds when the
			ECM main relay is commanded
			ON.
P1625	ECM Main Relay	The ignition switch is OFF.	The ECM detects that a high
	Circuit		voltage condition on the ECM
			main relay voltage feed circuit for
			longer than 5 seconds when the
			ECM main relay is commanded
			OFF.

Suspected Cause

ECM main relay coil side power supply circuit is open circuit or high resistance.

ECM main relay voltage feed circuit is open circuit or high resistance.

Faulty ECM main relay.

ECM main relay coil side power supply circuit is short to battery voltage circuit.

ECM main relay voltage feed circuit is short to battery voltage circuit.

Faulty ECM main relay.

N*R 4HK1-TC Engine-15

The engine control module (ECM) provides 5volts reference voltage through the reference circuit 1, 2, 3, 4 and 5 to the following sensors.

5volts reference circuit 1

Accelerator pedal position (APP) sensor 1 Idle up volume sensor

Remote PTO accelerator sensor 5volts reference circuit 2

APP sensor 2

Barometric pressure (BARO) sensor 5volts reference circuit 3 (Not Used) 5volts reference circuit 4

Boost pressure sensor 5volts reference circuit 5

Fuel rail pressure (FRP) sensor EGR valve position sensor

N*R 4HK1-TC Engine-16

Related DTC

DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC
	Tool
P1631	5 Volt Reference	DTC P1630 is not set.	The ECM detects that the 5 volts
	Circuit 1	The battery voltage is between 16	reference circuit 1 voltage is less
		– 32 volts.	than 4.5 volts.
		The ignition switch is ON.	OR
			The ECM detects that the 5 volts
			reference circuit 1 voltage is more
			than 5.5 volts.

P1632	5 Volt Reference	DTC P1630 is not set.	The ECM detects that the 5 volts
	Circuit 2	The battery voltage is between 16	reference circuit 2 voltage is less
		– 32 volts.	than 4.5 volts.
		The ignition switch is ON.	OR
			The ECM detects that the 5 volts
			reference circuit 2 voltage is more
			than 5.5 volts.

Suspected Cause

APP sensor 1 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit.

Idle up sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit.

PTO accelerator sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit. Faulty APP sensor 1.

Faulty Idle up sensor.

Faulty PTO accelerator sensor. Faulty ECM.

Notice: APP sensor 1 is internal to APP sensor assembly.

APP sensor 2 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit.

BARO sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit.

Faulty APP sensor 2. Faulty BARO sensor. Faulty ECM.

Notice: APP sensor 2 is internal to APP sensor assembly.

N*R 4HK1-TC Engine-17

Related DTC

DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC
	Tool
P1633	5 Volt Reference	DTC P1630 is not set.	The ECM detects that the 5 volts
	Circuit 3	The battery voltage is between 16	reference circuit 3 voltage is less
		– 32 volts.	than 4.5 volts.
		The ignition switch is ON.	OR
			The ECM detects that the 5 volts
			reference circuit 3 voltage is more
			than 5.5 volts.
P1634	5 Volt Reference	DTC P1630 is not set.	The ECM detects that the 5 volts
	Circuit 4	The battery voltage is between 16	reference circuit 4 voltage is less
		– 32 volts.	than 4.5 volts.
		The ignition switch is ON.	OR
			The ECM detects that the 5 volts
			reference circuit 4 voltage is more
			than 5.5 volts.

Suspected Cause

-

Boost pressure sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit. Faulty boost pressure sensor.

Faulty ECM.

N*R 4HK1-TC Engine-18

Related DTC

DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC
	Tool
P1635	5 Volt Reference	DTC P1630 is not set.	The ECM detects that the 5 volts
	Circuit 5	The battery voltage is between 16	reference circuit 5 voltage is less
		– 32 volts.	than 4.5 volts.
		The ignition switch is ON.	OR
			The ECM detects that the 5 volts
			reference circuit 5 voltage is more
			than 5.5 volts.

Suspected Cause

FRP sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit.

EGR valve position sensor 5V reference circuit is short to ground, short to any 12V reference circuit, short to battery or ignition voltage circuit. Faulty FRP sensor.

Faulty EGR valve position sensor. Faulty ECM.

Notice: EGR valve position sensor is internal to EGR valve assembly.

N*R 4HK1-TC Engine-19

The engine control module (ECM), the smoother control module, ABS control module (EHCU) and the DMU, interchange of data among each controller performed via a controller area network (CAN) communication bus. Following signals are communicated via a CAN bus.

•Accelerator pedal position signal

•Engine output torque

•PTO control signal

•Exhaust brake cut signal

•Engine speed signal

•Injection volume reduction signal

The ECM monitors CAN operational status by expecting a constant flow of messages from each module. If the ECM fails to receive an expected message from each module, DTC U2104, U2106 or U2108 will set depending on what communication is lost.

					N*R 4HK1-TC Engine-20
Related DTC
DTC	DTC Name On Scan	Condition for Running the DTC		Condition for Setting the DTC	Suspected Cause
	Tool
					CAN high circuit is short to ground, short to
U2104	CAN Bus Reset	The ignition switch is ON.		The ECM detects that the CAN
	Counter Overrun			Bus OFF is detected.	battery or ignition voltage.
					CAN low circuit is short to ground, short to
					battery or ignition voltage.
					Electrical interference.
					Faulty ECM.
					Faulty TCM.
					Faulty EHCU.
					CAN high circuit is short to ground, short to
U2106	Lost CAN	The ignition switch is ON.		The ECM detects that the CAN
	Communications With			Bus messages from the TCM are	battery or ignition voltage.
	Transmission Control			not being received.	CAN low circuit is short to ground, short to
	System				battery or ignition voltage.
					Electrical interference.
					Faulty ECM.
					Faulty TCM.
					CAN high circuit is short to ground, short to
U2108	Lost Communications	The ignition switch is ON.		The ECM detects that the CAN
	With ABS/TCS Control			Bus messages from the EHCU	battery or ignition voltage.
	System			(ABS control unit) are not being	CAN low circuit is short to ground, short to
				received.	battery or ignition voltage.
					Electrical interference.
					Faulty ECM.
					Faulty EHCU.

N*R 4HK1-TC Engine-21

ELECTRICAL COMPONENTS

INTAKE AIR TEMPERATURE (IAT) SENSOR

The intake air temperature (IAT) sensor is fitted between the air cleaner and turbocharger. The IAT sensor is a variable resistor. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT sensor signal circuit and a ground for the IAT sensor low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT sensor signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT sensor signal circuit. The ECM uses to this value to calculate a fuel injection quantity, injection timing and EGR control.

	IAT Sensor Characteristic -Reference-					Ohms
						Volts
	30000					4.5
	27500					4
	25000
	22500					3.5
(Ohms)	20000					3
	17500					2.5
Resistance							Output (Volts)
	15000
	12500					2
						1.5
	10000
	7500					1
	5000
	2500					0.5
	0					0
-20 -10		0	10 20 30 40 50 60	70	80	90
			Temperature (C)

The characteristic of the IAT sensor is displayed in the graph and table. Calculated intake air temperature can be found on the Tech 2 by unit “°C” or “°F”. The output voltage also can be found on the Tech 2.

Notice!

In data display “°C” or “°F” will be fixed to a default value when DTC is set relating to the IAT sensor open or short circuit. To diagnose this DTC, observe the “Volts” in the data display.

°C	°F	Ohms	Volts
90	194	240	0.2
80	176	320	0.3
70	158	450	0.4
60	140	660	0.6
50	122	960	0.8
40	104	1440	1.1
30	86	2300	1.6
20	68	3430	2.1
10	50	5410	2.7
0	32	9770	3.3
-10	14	16410	3.8
-20	-4	28560	4.2

N*R 4HK1-TC Engine-22

IAT Sensor

Connector Face

Related DTC

	DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC	Suspected Cause
		Tool
					Sensor signal circuit is short to ground or short to
	P0112	Intake Air Temperature	DTCs P1630 and P1632 are not	The ECM detects that the IAT
		(IAT) Sensor Circuit	set.	sensor signal voltage is less than	the low reference circuit.
		Low Voltage	The ignition switch is ON.	0.1 volts for 5 seconds.	Faulty IAT sensor.
			The ignition voltage is more than 18		Faulty ECM.
			volts.
					Sensor signal circuit is open circuit, high
	P0113	Intake Air Temperature	DTCs P1630 and P1632 are not	The ECM detects that the IAT
		(IAT) Sensor Circuit	set.	sensor signal voltage is more than	resistance, short to any 5V or 12V reference
		High Voltage	The ignition switch is ON.	4.8 volts for 5 seconds.	circuit, short to battery or ignition voltage circuit.
			The ignition voltage is more than 18		Sensor low reference circuit is open circuit or
			volts.		high resistance.
			The engine run time is longer than		Poor harness connector connection.
					Faulty IAT Sensor.
			3 minutes.
					Faulty ECM.

N*R 4HK1-TC Engine-23

ENGINE COOLTANT TEMPERATURE (ECT) SENSOR

	ECT Sensor Characteristic -Reference-									Ohms
										Volts
	28000									5
	26000									4.5
	24000
	22000									4
	20000									3.5
Resistance (Ohms)	18000									3
	16000										Output (Volts)
	14000									2.5
	12000									2
	10000
		8000								1.5
		6000								1
		4000								0.5
		2000
		0								0
-3	-2	-1	0	10	20 30 40 50 60	70	80	90	10	11
0	0	0			Temperature (C)				0	0

°C	°F	Ohms	Volts
110	230	160	0.2
100	212	200	0.3
90	194	260	0.4
80	176	350	0.5
70	158	470	0.6
60	140	640	0.8
50	122	880	1.1
40	104	1250	1.5
30	86	1800	1.9
20	68	2650	2.3
10	50	4000	2.8
0	32	6180	3.3
-10	14	9810	3.8
-20	-4	16000	4.2
-30	-22	27000	4.5

The engine coolant temperature (ECT) sensor is installed to the coolant stream on the thermostat housing. It is a variable resistor. The ECT sensor measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT sensor signal circuit and a ground for the ECT sensor low reference circuit. When the ECT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT sensor signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT sensor signal circuit. The ECM uses to this value to calculate a fuel injection quantity, injection timing and EGR control and preheating control.

1.Engine Coolant Temperature (ECT) Sensor

The characteristic of the ECT sensor is displayed in the graph and table. Calculated coolant temperature can be found on the Tech 2 by unit “°C” or “°F“. The output voltage also can be found on the Tech 2.

Notice!

In data display “°C” or “°F” will be fixed to a default value when DTC is set relating to the ECT sensor. To diagnose this DTC, observe the “Volts” in the data display.

N*R 4HK1-TC Engine-24

ECT Sensor

Connector Face

Related DTC

	DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC	Suspected Cause
		Tool
					Sensor signal circuit is short to ground or short to
	P0117	Engine Coolant	DTCs P1630 and P1634 are not	The ECM detects that the ECT
		Temperature (ECT)	set.	sensor signal voltage is less than	the low reference circuit.
		Sensor Circuit Low	The ignition switch is ON.	0.1 volts for 5 seconds.	Faulty ECT sensor.
		Voltage	The ignition voltage is more than		Faulty ECM.
			18 volts.
					Sensor signal circuit is open circuit, high
	P0118	Engine Coolant	DTCs P1630 and P1634 are not	The ECM detects that the ECT
		Temperature (ECT)	set.	sensor signal voltage is more than	resistance, short to any 5V or 12V reference
		Sensor Circuit High	The ignition switch is ON.	4.8 volts for 5 seconds.	circuit, short to battery or ignition voltage circuit.
		Voltage	The ignition voltage is more than		Sensor low reference circuit is open circuit or
			18 volts.		high resistance.
			The engine run time is longer than		Poor harness connector connection.
			3 minutes.		Faulty ECT Sensor.
					Faulty ECM.
					Engine overheat.
	P1173	Engine Overheat	DTCs P0117, P0118, P1630 and	The ECM detects that the ECT is
			P1634 are not set.	more than 110°C (230°F) for 5	Faulty engine cooling system
			The ignition switch is ON.	seconds.	Faulty ECT sensor.
			The ignition voltage is more than
			18 volts.
			The engine is running.

N*R 4HK1-TC Engine-25

FUEL TEMPERATURE (FT) SENSOR

The fuel temperature (FT) sensor is installed to the supply pump. It is a variable resistor. The FT sensor measures the temperature of the fuel. The engine control module (ECM) supplies 5volts to the FT sensor signal circuit and a ground for the FT sensor low reference circuit. When the FT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the FT sensor signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the FT sensor signal circuit. The ECM uses to this value to calculate a fuel injection volume, injection timing and EGR control.

1. Fuel Temperature (FT) Sensor

2. Suction Control Valve (SCV)

		FT Sensor Characteristic -Reference-					Ohms
							Volts
		26000
							5
		24000					4.5
		22000
							4
		20000
		18000					3.5
(Ohms)		16000					3
		14000					2.5
		12000
								(Volts)
Resistance		10000					2	Output
		8000
							1.5
		6000					1
		4000
							0.5
		2000
		0					0
-30	-20	-10	0	10 20 30 40 50 60 70	80	90	100 110
				Temperature (C)

°C	°F	Ohms	Volts
110	230	140	0.2
100	212	180	0.3
90	194	240	0.4
80	176	310	0.5
70	158	420	0.6
60	140	580	0.9
50	122	810	1.1
40	104	1150	1.5
30	86	1660	1.8
20	68	2450	2.3
10	50	3700	2.8
0	32	5740	3.3
-10	14	9160	3.8
-20	-4	15000	4.2
-30	-22	25400	4.5

The characteristic of the FT sensor is displayed in the graph and table. Calculated coolant temperature can be found on the Tech 2 by unit “°C” or “°F “. The output voltage also can be found on the Tech 2.

Notice!

In data display “°C” or “°F” will be fixed to a default value when DTC is set relating to the FT sensor. To diagnose this DTC, observe the “Volts” in the data display.

N*R 4HK1-TC Engine-26

FT Sensor

Connector Face

Related DTC

	DTC	DTC Name On Scan	Condition for Running the DTC	Condition for Setting the DTC	Suspected Cause
		Tool
					Sensor signal circuit is short to ground or short to
	P0182	Fuel Temperature	DTCs P1630 and P1634 are not	The ECM detects that the FT
		Sensor Circuit Low	set.	sensor signal voltage is less than	the low reference circuit.
		Voltage	The ignition switch is ON.	0.1 volts for 5 seconds.	Faulty FT sensor.
			The ignition voltage is more than		Faulty ECM.
			18 volts.
					Sensor signal circuit is open circuit, high
	P0183	Fuel Temperature	DTCs P1630 and P1634 are not	The ECM detects that the FT
		Sensor Circuit High	set.	sensor signal voltage is more than	resistance, short to any 5V or 12V reference
		Voltage	The ignition switch is ON.	4.8 votls for 5 seconds.	circuit, short to battery or ignition voltage circuit.
			The ignition voltage is more than		Sensor low reference circuit is open circuit or
			18 volts.		high resistance.
			The engine run time is longer than		Poor harness connector connection.
			3 minutes.		Faulty FT Sensor.
					Faulty ECM.

N*R 4HK1-TC Engine-27

CRANKSHAFT POSITION (CKP) SENSOR & CAMSHAFT POSITION (CMP) SENSOR

The crankshaft position (CKP) sensor is located on top of the flywheel housing. There are 56 notches spaced 6deg. apart and a 30deg. section that is uncut. This uncut portion allows for the detection of top dead center (TDC). The CKP sensor is a magnet coil type sensor, which generates an AC signal voltage based on the crankshaft rotational speed. If the CKP sensor fails, the camshaft position (CMP) sensor signals will substitute for the CKP sensor signal backup.

1. Crankshaft Position (CKP) Sensor

2. Sensor Wheel

N*R 4HK1-TC Engine-28

The camshaft position (CMP) sensor is installed on the cylinder head at the rear of the camshaft. The CMP sensor detects a total five through holes, four reference holes arranged equally every 90deg. space and one reference hole on the camshaft gear flange surface, and sends signals to the engine control module (ECM). Receiving these signals, the ECM determines cylinder #1 compression top dead center (TDC). If the CMP sensor fails, the crankshaft position (CKP) sensor signals will NOT substitute for the CMP sensor signal backup. Engine cranks but does not start.

1.Camshaft Gear

2.Gear Rotating Direction

3.Camshaft Position (CMP) Sensor

N*R 4HK1-TC Engine-29

								No.1 TDC	No.3 TDC

6deg.CA	30deg.CA

CH1

0V

CH2	30deg.CA	90deg.CA	No.1 TDC
0V

			90deg.CA							90deg.CA

The relationship of CKP sensor and CMP sensor is displayed on the above picture. The ECM detects 112 CKP sensor pulses (56 x 2) and 5 CMP sensor pulses per 2 crankshaft rotations (720 deg.CA). Both sensor wheels are mechanically bit with each other. Therefore, the relationship of each pulse is always constant. The injection timing suitable for the vehicle conditions is controlled based on the inputs from respective sensors.