Mitsubishi L200. Manual - part 66

TROUBLESHOOTING

DIESEL FUEL

13A-60

• Based on The input signals, the engine-ECU 

checks whether the fuel pressure in the common 
rail exceeds the maximum withstand pressure of 
the system.

TROUBLE JUDGMENT

Check Conditions

• Rail pressure sensor is normal

• Battery positive voltage is 8 − 16 V

Judgment Criterion

• The rail pressure exceeds the threshold value of 

an abnormal high pressure for 3 seconds (contin-
uous or accumulated).

PROBABLE CAUSES

• Failed suction control valve

• Failed rail pressure sensor

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is any other diagnosis code than P0088 output?

YES : 

Inspection chart for diagnosis codes (Refer 

to 

P.13A-21

).

NO : 

Go to Step 2 .

STEP 2. Check suction control valve itself

• Check suction control valve itself (Refer to 

P.13A-

596

).

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Replace the suction control valve. After 
replacing the suction control valve, learn the 
supply pump (Refer to GROUP 00 

− 

Precautions Before Service 

− What The 

Common Rail Engine Learns ).

STEP 3. Connector check: C-105 engine-ECU 
connector and A-47 suction control valve 
connector.

Q: Are the check results normal?

YES : 

Go to Step 4 .

NO : 

Repair or replace the connector.

AKA00089

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C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

AK503644

2

1

A-47 (GR)

Harness side 
connector

AB

Connector: A-47

TROUBLESHOOTING

DIESEL FUEL

13A-61

STEP 4. Check harness between C-105 (terminal 
No. 131) engine-ECU connector and A-47 
(terminal No. 1) suction control valve connector.

• Check output line for open/short circuit and dam-

age.

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair the damaged harness wire.

STEP 5. Check harness between C-105 (terminal 
No. 146) engine-ECU connector and A-47 
(terminal No. 2) suction control valve connector.

• Check output line for open/short circuit and dam-

age.

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair the damaged harness wire.

AKA00089

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C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

AK503644

2

1

A-47 (GR)

Harness side 
connector

AB

Connector: A-47

AKA00089

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C-105 (B)

C-105 (B)

<R.H. drive vehicles>

Harness side connector

<L.H. drive vehicles>

Connector: C-105

AB

AK503644

2

1

A-47 (GR)

Harness side 
connector

AB

Connector: A-47

TROUBLESHOOTING

DIESEL FUEL

13A-62

STEP 6. Perform output wave pattern 
measurement at A-47 suction control valve 
(Using an oscilloscope).

• Engine: Idling

• Connect the oscilloscope special patterns pickup 

to engine-ECU terminal No. 146 and earth.

OK: The waveform should show a pattern 
similar to the illustration of inspection proce-
dure using an oscilloscope (Refer to 

P.13A-

586

).

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Replace the suction control valve. After 
replacing the suction control valve, learn the 
supply pump (Refer to GROUP 00 

− 

Precautions Before Service 

− What The 

Common Rail Engine Learns ).

STEP 7. Replace the common rail assembly and 
fuel injection tubes.

• After replacing the common rail assembly and 

fuel injection tubes, re-check the trouble symp-
toms

Q: Does trouble symptom persist?

YES : 

Replace the engine-ECU. When the engine-

ECU is replaced, write the chassis number 
(Refer to GROUP 00 

− Precautions Before 

Service 

− How to Perform Chassis Number 

Writing ). After replacing the engine-ECU, 
register the injector identification code and 
learn fuel injection (Refer to GROUP 00 

− 

Precautions Before Service 

− What The 

Common Rail Engine Learns ). After 
registering the injector identification code, 
the vehicle equipped with the DPF carries 
out the forcible DPF regeneration. (Refer to 
GROUP 17 

− Emission Control − Diesel 

Particulate Filter (DPF) System 

− Forcible 

DPF Regeneration ).

NO : 

The check is end.

Code No. P0089: Suction Control Valve Stuck

OPERATION

• Battery power is supplied from the engine-ECU 

(terminal No. 131) to the suction control valve 
(terminal No. 1).

• The engine-ECU (terminal No. 146) turns on the 

power transistor to flow current to the suction 
control valve (terminal No. 2).

FUNCTION

• The engine-ECU monitors the signals input from 

the rail pressure sensor.

• The engine-ECU monitors the difference between 

the target fuel pressure and actual fuel pressure 
to check whether the suction control valve is 
open or fixed.

TROUBLE JUDGMENT

Check Conditions

• Battery positive voltage is 8 − 16 V

• 2 seconds later after the ignition switch has been 

in "ON" position or the engine has started up

Judgment Criterion

• The actual rail pressure remains higher than the 

objective rail pressure by 10 MPa or more for a 
certain interval.

PROBABLE CAUSES

• Failed suction control valve

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III actuator test.

• Refer to Actuator Test Table 

P.13A-574

.

a. Item 19: Suction control valve

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Go to Step 4 .

AK503644

2

1

A-47 (GR)

Harness side 
connector

AB

Connector: A-47

TROUBLESHOOTING

DIESEL FUEL

13A-63

STEP 2. Make a check on the following items.

• Check for foreign matters (water, kerosene, etc.) 

in fuel and replace if necessary.

• Check fuel filter itself.

Q: Are the check results normal?

YES : 

Go to Step 3 .

NO : 

Make a repair or replacement for items 
whose checking results are abnormal.

STEP 3. M.U.T.-III diagnosis code.

• Reconfirmation of diagnosis code

Q: Is the diagnosis code set?

YES : 

Replace the engine-ECU. When the engine-

ECU is replaced, write the chassis number 
(Refer to GROUP 00 

− Precautions Before 

Service 

− How to Perform Chassis Number 

Writing ). After replacing the engine-ECU, 
register the injector identification code and 
learn fuel injection (Refer to GROUP 00 

− 

Precautions Before Service 

− What The 

Common Rail Engine Learns ). After 
registering the injector identification code, 
the vehicle equipped with the DPF carries 
out the forcible DPF regeneration. (Refer to 
GROUP 17 

− Emission Control − Diesel 

Particulate Filter (DPF) System 

− Forcible 

DPF Regeneration ).

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use Troubleshooting/

Inspection Service Points 

− How to Cope 

with Intermittent Malfunctions ).

STEP 4. Replace the suction control valve.

• After the suction control valve, learn the supply 

pump. (Refer to GROUP 00 

− Precautions Before 

Service 

− What The Common Rail Engine Learns 

).

• After learning the supply pump assembly, re-

check the trouble symptoms

Q: Does trouble symptom persist?

YES : 

Replace the engine-ECU. When the engine-

ECU is replaced, write the chassis number 
(Refer to GROUP 00 

− Precautions Before 

Service 

− How to Perform Chassis Number 

Writing ). After replacing the engine-ECU, 
register the injector identification code and 
learn fuel injection (Refer to GROUP 00 

− 

Precautions Before Service 

− What The 

Common Rail Engine Learns ). After 
registering the injector identification code, 
the vehicle equipped with the DPF carries 
out the forcible DPF regeneration. (Refer to 
GROUP 17 

− Emission Control − Diesel 

Particulate Filter (DPF) System 

− Forcible 

DPF Regeneration ).

NO : 

The check is end.

Code No. P0093: Fuel Leak Problem

OPERATION

• Refer to Code No. P0192: Rail Pressure Sensor 

Circuit Low Input 

P.13A-147

.

FUNCTION

• The engine-ECU monitors the signals input from 

the rail pressure sensor.

• The engine-ECU controls the suction control 

valve so that necessary fuel pressure can be 
obtained before fuel injection.

• The engine-ECU compares the fuel pressure 

immediately before fuel injection and the fuel 
pressure after injection to check whether. The 
pressure drop greatly exceeds the expected 
range determined based on fuel consumption. 
The engine-ECU detects fuel leaks in this way.

TROUBLE JUDGMENT

Check Conditions

• Battery positive voltage is 8 − 16 V

• 2 seconds later after the ignition switch has been 

in "ON" position or the engine has started up

• The engine speed is 600 r/min or more

• Rail pressure sensor is normal

Judgment Criterion

• The fuel discharge rate of the supply pump con-

tinues to exceed its threshold value against the 
fuel injection rate.

PROBABLE CAUSES

• Fuel leakage or fuel line blocked

• Failed injector

• Failed suction control valve