Mitsubishi 4D56, 4M41 Repair Manual

Common Rail System (HP3) for MITSUBISHI TRITON

4D56/4M41 Engine

DENSO INTERNATIONAL THAILAND CO., LTD

00400554E

© 2005 DENSO CORPORATION

All Rights Reserved. This book may not be reproduced or copied, in whole or in part, without the written permission of the publisher.

		Revision History
	Revision History
	Date	Revision Contents
	2005.10.25	Portions of 14.2 Diagnostic Trouble Code Datails" revised. (See P1-37, 38, 39, 40, 41)
		"15.1 Engine ECU Externa Wring Diagram illustration (Applicable Illust. code: Q001257E,
		Q001258E) replaced. (See P1-42, 43)
		Portions of the "15.2 Engine ECU Connector Diagram Terminal Connections (1), (2), (3) replaced .
		(See P1-43, 44, 45)

Table of Contents

Operation Section

1.PRODUCT APPILCATION INFORMATION

1.1	Application ..................................................	1-1
1.2	System Components Part Number .............	1-1

2.	OUTLINE OF SYSTEM
2.1	Common Rail System Characteristics ........	1-2
2.2	Features of Injection Control.......................	1-2
2.3	Comparison to the Conventional System....	1-3
2.4	Composition ................................................	1-3
2.5	Operation ....................................................	1-4
2.6	Fuel System ................................................	1-4
2.7	Control System ...........................................	1-4

3.	SUPPLY PUMP
3.1	Outline.........................................................	1-6
3.2	Exterior View Diagram ................................	1-7
3.3	Supply Pump Internal Fuel Flow .................	1-7
3.4	Construction of Supply Pump .....................	1-8
3.5	Operation of the Supply Pump....................	1-9

4.SUPPLY PUMP COMPONENT PARTS

4.1	Feed Pump ................................................	1-11
4.2	SCV ( Suction Control Valve ) ....................	1-11
4.3	Fuel Temperature Sensor .........................	1-13

5.	RAIL
5.1	Outline.......................................................	1-14
6. RAIL COMPONENTS PARTS
6.1	Rail Pressure Sensor (Pc Sensor) ............	1-15
6.2	Pressure limiter .........................................	1-15

7.	INJECTOR (G2 TYPE)
7.1	Outline.......................................................	1-16
7.2	Characteristics ..........................................	1-16
7.3	Exterior View Diagram ..............................	1-17
7.4	Construction ..............................................	1-18
7.5	Operation ..................................................	1-18
7.6	QR Codes .................................................	1-19
7.7	Injector Actuation Circuit ...........................	1-21

8.OPERATION OF CONTROL SYSTEM COMPONENTS

8.1	Engine Control System Diagram...............	1-22
8.2	Engine ECU (Electronic Control Unit) .......	1-22
8.3	Cylinder Recognition Sensor (TDC)..........	1-23
8.4	Turbo Pressure Sensor .............................	1-23
8.5	Mass Air Flow Sensor ...............................	1-24
8.6	Electronic Control Throttle ........................	1-25

9. VARIOUS TYPES OF CONTROL

9.1	Outline.......................................................	1-27
9.2	Fuel Injection Rate Control Function.........	1-27
9.3	Fuel Injection Quantity Control Function ...	1-27
9.4	Fuel Injection Timing Control Function......	1-27

9.5Fuel Injection Pressure Control Function (Rail

Pressure Control Function) .............

1-27

10.FUEL INJECTION QUANTITY CONTROL

10.1	Outline.......................................................	1-28
10.2	Injection Quantity Calculation Method ......	1-28
10.3	Set Injection Quantities .............................	1-28

Table of Contents

11.FUEL INJECTION TIMING CONTROL

11.1	Ouline........................................................	1-32
11.2	Main and Pilot Injection Timing Control.....	1-32
11.3	Microinjection Quantity Learning Control ..	1-33

12.FUEL INJECTION RATE CONTROL

12.1 Outline.......................................................

1-35

13.FUEL INJECTION PRESSURE CONTROL

13.1 Fuel Injection Pressure .............................

1-36

14.DIAGNOSTIC TROUBLE CODES (DTC)

14.1	About the Codes Shown in the Table........	1-37
14.2	Diagnostic Trouble Code Details...............	1-37

15. EXTERNAL WIRING DIAGRAM

15.1	Engine ECU External Wiring Diagram ......	1-42
15.2	Engine ECU Connector Diagram ..............	1-43

Operation Section

1 1

1.PRODUCT APPILCATION INFORMATION

1.1Application

		Vehicle Manufac-	Vehicle Name			Engine Model			Specification	Destination (Vol-	Line Off Period
		ture								ume)
					4D56				2WD (MT/AT)
		MITSUBISHI	TRITON							Thailand	June, 2005
									4WD (MT)
					4M41				4WD (MT/AT)
1.2 System Components Part Number
		Parts Name		DENSO P/N				Manufacturer P/N		Remarks
	Supply pump			SM294000-0331			1460A001			For 4D56 Engine Model
				SM294000-0341			1460A003			For 4M41 Engine Model
	Injector			SM095000-5600			1465A041			For 4D56 Engine Model
				SM095000-5760			1465A054			For 4M41 Engine Model
	Rail			SM095440-0640			1465A034			ALL
	Engine ECU			MA275800-425#			1860A392			For 4D56 Engine Model (4WD)
				MA275800-431#			1860A523			For 4D56 Engine Model (2WD MT)
				MA275800-432#			1860A524			For 4D56 Engine Model (2WD AT)
				MA275800-357#			1860A390			For 4M41 Engine Model (4WD)
	Turbo pressure sensor			079800-5960			MR577031			ALL
	Cylinder recognition		sensor	949979-1590			1865A074			For 4M41 Engine Model
	(TDC)
	Electronic control throttle			197920-0020			1450A033			For 4M41, 4D56 Engine Model (4WD)
	Fuel temperature sensor			179730-0020			MR547077			ALL
	Mass air flow meter			VN197400-4030			1460A001			ALL

Operation Section

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2.OUTLINE OF SYSTEM

2.1Common Rail System Characteristics

The common rail system uses a type of accumulation chamber called a rail to store pressurized fuel, and injectors that contain electronically controlled solenoid valves to inject the pressurized fuel into the cylinders. Because the engine ECU controls the injection system (injection pressure, injection rate, and injection timing), the injection system is independent, and thus unaffected by the engine speed or load. This ensures a stable injection pressure at all times, particularly in the low engine speed range, and dramatically decreases the amount of black smoke ordinarily emitted by a diesel engine during start-up and acceleration. As a result, exhaust gas emissions are cleaner and reduced, and higher power output is achieved.

2.2 Features of Injection Control

(1)Injection Pressure Control

Enables high-pressure injection even at low engine speeds.

Optimizes control to minimize particulate matter and NOx emissions.

(2)Injection Timing Control

Enables finely tuned optimized control in accordance with driving conditions.

(3)Injection Rate Control

Pilot injection control injects a small amount of fuel before the main injection.

		Operation Section
		1 3
2.3 Comparison to the Conventional System
In-line, VE Pump		Common Rail System
System

Injection	Pump (Governor)		Engine ECU, Injector (TWV)*1
Quantity
Control
Injection	Pump (Timer)		Engine ECU, Injector (TWV)*1
Timing
Control
Rising	Pump		Engine ECU, Supply Pump
Pressure
Distributor	Pump		Engine ECU, Rail
Injection	Dependent upon Speed and Injection Quantity		Engine ECU, Supply Pump (SCV)*2
Pressure
Control

< NOTE >

*1 : TWV: Two Way Valve

*2 : SCV: Suction Control Valve

2.4 Composition

The common rail system consists primarily of a supply pump, rail, injectors, and engine ECU.

Operation Section

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2.5 Operation

(1)Supply Pump (HP3)

The supply pump draws fuel from the fuel tank, and pumps the high pressure fuel to the rail. The quantity of fuel discharged from the supply pump controls the pressure in the rail. The SCV (Suction Control Valve) in the supply pump effects this control in accordance with commands received from the engine ECU.

(2)Rail

The rail is mounted between the supply pump and the injector, and stores the high-pressure fuel.

(3)Injector (G2 type)

This injector replaces the conventional injection nozzle, and achieves optimal injection by effecting control in accordance with signals from the engine ECU. Signals from the engine ECU determine the duration and timing in which current is applied the injector. This in turn, determines the quantity, rate and timing of the fuel that is injected from the injector.

(4)Engine ECU

The engine ECU calculates data received from the sensors to comprehensively control the injection quantity, timing and pressure, as well as the EGR (exhaust gas recirculation).

2.6 Fuel System

This system comprises the route through which diesel fuel flows from the fuel tank via the rail to the supply pump, and is injected through the injector, as well as the route through which the fuel returns to the tank via the overflow pipe.

2.7 Control System

In this system, the engine ECU controls the fuel injection system in accordance with signals received from various sensors. The components of this system can be broadly divided into the following three types: (1) sensors; (2) ECU; and (3) actuators.

Operation Section

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(1)Sensors

Detect the engine and driving conditions, and convert them into electrical signals.

(2)Engine ECU

Performs calculations based on the electrical signals received from the sensors, and sends them to the actuators in order to achieve optimal conditions.

(3)Actuators

Operate in accordance with electrical signals received from the ECU. Injection system control is undertaken by electronically controlling the actuators. The injection quantity and timing are determined by controlling the duration and timing in which current is applied to the TWV (Two-Way Valve) in the injector. Injection pressure is determined by controlling the SCV (Suction Control Valve) in the supply pump.

Operation Section

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3. SUPPLY PUMP

3.1 Outline

The supply pump consists primarily of the pump body (eccentric cam, ring cam, and plungers), SCV (Suction Control Valve), fuel temperature sensor, and feed pump.

The two plungers are positioned vertically on the outer ring cam for compactness.

The engine drives the supply pump at a ratio of 1:1. The supply pump has a built-in feed pump (trochoid type), and draws the fuel from the fuel tank, sending it to the plunger chamber.

The internal camshaft drives the two plungers, and they pressurize the fuel sent to the plunger chamber and send it to the rail. The quantity of fuel supplied to the rail is controlled by the SCV, using signals from the engine ECU. The SCV is a normally open type (the intake valve opened during de-energization).

Operation Section

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3.2 Exterior View Diagram

4D56 Engine Model

4M41 Engine Model

3.3 Supply Pump Internal Fuel Flow

The fuel that is drawn from the fuel tank passes through the route in the supply pump as illustrated, and is fed into the rail.

Operation Section

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3.4 Construction of Supply Pump

The eccentric cam is attached to the drive shaft. The eccentric cam is connected to the ring cam.

As the drive shaft rotates, the eccentric cam rotates eccentrically, and the ring cam moves up and down while rotating.

The plunger and the suction valve are attached to the ring cam. The feed pump is connected to the rear of the drive shaft.

Operation Section

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3.5 Operation of the Supply Pump

As shown in the illustration below, the rotation of the eccentric cam causes the ring cam to push Plunger A upwards. Due to the spring force, Plunger B is pulled in the opposite direction to Plunger A. As a result, Plunger B draws in fuel, while Plunger A pumps it to the rail.

Operation Section

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Operation Section

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4. SUPPLY PUMP COMPONENT PARTS

4.1 Feed Pump

The trochoid type feed pump, which is integrated in the supply pump, draws fuel from the fuel tank and feeds it to the two plungers via the fuel filter and the SCV (Suction Control Valve). The feed pump is driven by the drive shaft. With the rotation of the inner rotor, the feed pump draws fuel from its suction port and pumps it out through the discharge port. This is done in accordance with the space that increases and decreases with the movement of the outer and inner rotors.

4.2 SCV ( Suction Control Valve )

A linear solenoid type valve has been adopted. The ECU controls the duty ratio (the duration in which current is applied to the SCV), in order to control the quantity of fuel that is supplied to the high-pressure plunger.

Because only the quantity of fuel that is required for achieving the target rail pressure is drawn in, the actuating load of the supply pump decreases.

When current flows to the SCV, variable electromotive force is created in accordance with the duty ratio, moving the cylinder (integrated with the armature) to the left side, and changing the opening of the fuel passage to regulate the fuel quantity.

With the SCV OFF, the return spring contracts, completely opening the fuel passage and supplying fuel to the plungers. (Full quantity intake and full quantity discharge = normally open)

When the SCV is ON, the force of the return spring moves the cylinder to the left, closing the fuel passage (normally open).

By turning the SCV ON/OFF, fuel is supplied in an amount corresponding to the actuation duty ratio, and fuel is discharged by the plungers.