Mitsubishi Colt Ralliart. Manual - part 736

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-269

STEP 3. Perform voltage measurement at A-131 
alternator connector.

•

Disconnect connector and measure at harness side.

• Ignition switch: ON

• Voltage between terminal No. 3 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Go to Step 4 .

STEP 4. Connector check: B-141 ignition switch 
connector

Q: Is the check result normal?

YES : 

Check intermediate connectors A-17, B-41, 

B-14, B-22, B-131, B-129, and repair if 
necessary. If intermediate connectors are 
normal, check and repair harness between 
B-141 (terminal No. 2) ignition switch 
connector and A-131 (terminal No. 3) 
alternator connector.

• Check power supply line for 

open/short circuit.

NO : 

Repair or replace.

STEP 5. Connector check: A-114 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair or replace.

2

1

3

4

AK402098

A-131(G)

Connector: A-131

Harness side 
connector

AC

1

2

3

4

5

6

AK402103

Connector: B-141

Harness side 
connector

B-141

AC

2

1

3

4

AK402098

A-131(G)

Connector: A-131

Harness side 
connector

AC

AK402745

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L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-270

STEP 6. Perform voltage measurement at A-114 
engine-ECU connector.

•

Disconnect connector and measure at harness side.

• Ignition switch: ON

• Voltage between terminal No. 64 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 7 .

STEP 7. Check harness between A-131 (terminal 
No. 1) alternator connector and A-114 (terminal 
No. 64) engine-ECU connector.

•

Check output line for open/short circuit.

Q: Is the check result normal?

YES : 

Replace alternator.

NO : 

Repair.

AK402745

6

4

2

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3

1

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L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

2

1

3

4

AK402098

A-131(G)

Connector: A-131

Harness side 
connector

AC

AK402745

6

4

2

5

3

1

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L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-271

STEP 8. Perform voltage measurement at A-114 
engine-ECU connector.

•

Disconnect engine-ECU connector, and connect 

Special Tool Power Plant ECU Check Harness 
(MB991987), and measure the voltage on the 
check connector.

• Engine: Idling after warm-up

• Transmission: Neutral

• Cooling fan: Inactive

• Voltage between terminal No. 64 and earth.

OK: Switching the headlamps to ON from 
OFF causes the voltage to increase 0.2 

− 3.5 

V.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Check alternator.

STEP 9. Check the trouble symptom.

Q: Does trouble symptom recur?

YES : 

Replace engine-ECU.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunctions 

P.00-13

).

AK402745

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L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-272

Inspection Procedure 18: Overheating

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by failed engine cool-

ing system, failed engine coolant temperature 
sensor, or other faults.

PROBABLE CAUSES

• Lack of or deteriorated engine coolant

• Failed fan control relay

• Failed engine coolant temperature sensor

• Failed thermostat

• Failed water pump

• Failed radiator core

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2.

STEP 2. Check engine coolant.
NOTE: If engine coolant level falls too early, check 
for leaky spots, and repair if necessary.

• Check engine coolant (Refer to GROUP 14 − 

On-vehicle Service 

− Engine Coolant Leak Check 

P.14-3

).

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace or add engine coolant.

STEP 3. M.U.T.-III actuator test

• Refer to Actuator Test Reference Table 

P.13B-344

.

a. Item 20: Cooling fan motor (HI)
b. Item 21: Cooling fan motor (LO)

Q: Are the check result normal?

YES : 

Go to Step 4.

NO : 

Check fan control relay system (Refer to 
Inspection Procedure 23 

P.13B-303

).

STEP 4. M.U.T.-III data list

• Item 21: Engine coolant temperature sensor

OK: 

Engine cold state: At ambient temperature 

(atmospheric temperature) or equivalent.

Engine hot state: At 80 

− 120°C

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Check engine coolant temperature sensor 
(Refer to Code No. P0115 

P.13B-45

).

STEP 5. Check thermostat.

• Check thermostat (Refer to GROUP 14 − Ther-

mostat 

− Thermostat Inspection 

P.14-12

).

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Replace thermostat.

STEP 6. Check water pump.

• Check water pump.

Q: Is the check result normal?

YES : 

Replace radiator.

NO : 

Replace water pump.

Main

Index

Group

TOC