Mitsubishi L200. Manual — part 126

TROUBLESHOOTING

DIESEL FUEL

13A-300

• Failed supply pump

• Failed engine-ECU

DIAGNOSIS PROCEDURE

NOTE: This diagnosis code is outputted for an air
penetration in the fuel line of the supply pump due to
lack of fuel. Therefore, bleed air from the fuel line
after the fuel supply, and delete the diagnosis code
through M.U.T.-III.

STEP 1. M.U.T.-III diagnosis code

• With the air released from the fuel line, supply

fuel if necessary.

• Continue idle operation for about 5 minutes.

Q: Is the diagnosis code P1273 outputted again?

YES :

Go to Step 2 .

NO :

The check is end.

STEP 2. Replace the supply pump assembly.

• After the supply pump assembly, learn the sup-

ply 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. P1274: Supply Pump Protection

OPERATION

• Refer to Code No. P0191: Rail Pressure Sensor

Range/Performance Problem

P.13A-143

.

• Refer to Code No. P0192: Rail Pressure Sensor

Circuit Low Input

P.13A-147

.

• Refer to Code No. P0193: Rail Pressure Sensor

Circuit High Input

P.13A-155

.

FUNCTION

• The engine-ECU monitors the signals input from

the rail pressure sensor.

• Based on these input signals, the engine-ECU

checks whether the fuel pressure in the common
rail is abnormal.

TROUBLE JUDGMENT

Check Conditions

• Engine is running

• Rail pressure sensor is normal

Judgment Criterion

• For 1 seconds, the rail pressure stays in the criti-

cal pressure range in which the supply pump is
burned out.

PROBABLE CAUSES

• Failed supply pump

• Failed common rail assembly

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is any other diagnosis code than P1274 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 supply pump, learn the supply
pump (Refer to GROUP 00

− Precautions

Before Service

− What The Common Rail

Engine Learns ).

TROUBLESHOOTING

DIESEL FUEL

13A-301

STEP 3. Replace the supply pump assembly.

• After the supply pump assembly, learn the sup-

ply 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 :

Go to Step 4 .

NO :

The check is end.

STEP 4. 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. P1275: Supply Pump Exchange

OPERATION

• Refer to Code No. P0191: Rail Pressure Sensor

Range/Performance Problem

P.13A-143

.

• Refer to Code No. P0192: Rail Pressure Sensor

Circuit Low Input

P.13A-147

.

• Refer to Code No. P0193: Rail Pressure Sensor

Circuit High Input

P.13A-155

.

FUNCTION

• The engine-ECU monitors the signals input from

the rail pressure sensor.

• Based on these input signals, the engine-ECU

checks whether the fuel pressure in the common
rail is abnormal.

TROUBLE JUDGMENT

Check Conditions

• Engine is running

• Rail pressure sensor is normal

Judgment Criterion

• The rail pressure continues to exceed the maxi-

mum operating pressure of the supply pump for
15 seconds.

PROBABLE CAUSES

• Failed supply pump

• Failed rail pressure sensor

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is any other diagnosis code than P1275 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. Replace the supply pump.

• After the supply pump assembly, learn the supply

pump. (Refer to GROUP 00

− Precautions Before

Service

− What The Common Rail Engine Learns

).

• After learning the supply pump, re-check the trou-

ble symptoms.

Q: Does trouble symptom persist?

YES :

Go to Step 4 .

NO :

The check is end.

TROUBLESHOOTING

DIESEL FUEL

13A-302

STEP 4. 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.

TROUBLESHOOTING

DIESEL FUEL

13A-303

Code No. P1276: Fuel Filter Exchange <Vehicles with fuel filter pressure switch>

OPERATION

• The battery voltage is applied to the fuel filter

pressure switch (terminal No. 1) from the engine-
ECU (terminal No. 110).

FUNCTION

• The engine-ECU detects the clogged fuel filter by

using the fuel filter pressure switch installed on
the fuel filter assembly.

TROUBLE JUDGMENT

Check Condition

• During steady driving after engine warm up.

Judgment Criterion

• Determination of clogged fuel filter.

PROBABLE CAUSES

• Failed fuel filter pressure switch

• Open/short circuit or harness damage in fuel filter

pressure switch circuit or loose connector contact

• Failed engine-ECU

AKB00283

99

100

111

110

101

128 129 130

2

1

101 102

103104 105 106107 108109 110 111112 113 114115

118119 120 121122 123124 125126127 128 129130

131132 133 134135 136137 138139140 141142 143

146147 148 149150 151152 153154155 156 157158

117

145

116

144

2

1

110

Fuel filter
pressure switch

ON

OFF

Engine-ECU

A-143

C-103

Fuel filter pressure switch circuit

W

B

Wire colour code
B: Black LG: Light green G: Green L: Blue W: White Y: Yellow SB: Sky blue BR: Brown O: Orange GR: Grey
R: Red P: Pink V: Violet PU: Purple

AB