Mitsubishi Grandis. Manual - part 766

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-315

STEP 5. Connector check: C-111 engine-ECU 
<M/T> connector or engine-A/T-ECU <A/T> 
connector

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair or replace.

STEP 6. Perform voltage measurement at C-111 
engine-ECU <M/T> connector or engine-A/T-ECU 
<A/T> connector

• Disconnect connector, and measure at harness 

side.

• Ignition switch: ON

• Voltage between terminal No. 45 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 7 .

AK305625AB

Connector: C-111

<L.H. drive vehicles>

<R.H. drive vehicles>

C-111 (GR)

C-111 (GR)

Harness side connector

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AK305625AB

Connector: C-111

<L.H. drive vehicles>

<R.H. drive vehicles>

C-111 (GR)

C-111 (GR)

Harness side connector

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TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-316

STEP 7. Check harness between C-111 (terminal 
No. 45) engine-ECU <M/T> or engine-A/T-ECU 
<A/T> and B-119 (terminal No. 1) alternator 
connector.

• Check output line for open/short circuit.

Q: Is the check result normal?

YES : 

replace alternator.

NO : 

Repair.

STEP 8. Perform voltage measurement at C-111 
engine-ECU <M/T> connector or engine-A/T-ECU 
<A/T> connector.

• Measure engine-ECU <M/T> or engine-A/T-ECU 

<A/T> terminal voltage.

• Engine: Idling after warm-up

• Transmission: Neutral <M/T> or P range <A/T>

• Radiator fan: Inactive

• Voltage between terminal No. 45 and earth.

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

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Replace alternator.

STEP 9. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES : 

Replace engine-ECU <M/T> or 

engine-A/T-ECU <A/T>.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

Inspection Procedure 20: Overheating

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by failed engine 

cooling system, failed fan controller, failed engine 

coolant temperature sensor or other faults.

AK305625AB

Connector: C-111

<L.H. drive vehicles>

<R.H. drive vehicles>

C-111 (GR)

C-111 (GR)

Harness side connector

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AK300990

2

1

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AC

B-119 (GR)

Connector: B-119

Harness side connector

AK305625AB

Connector: C-111

<L.H. drive vehicles>

<R.H. drive vehicles>

C-111 (GR)

C-111 (GR)

Harness side connector

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TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-317

PROBABLE CAUSE

• Insufficient or deteriorated engine coolant

• Failed fan controller

• Failed engine coolant temperature sensor

• Failed thermostat

• Failed water pump

• Failed radiator core

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. MUT-III diagnosis code

Q: Diagnosis code set?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13A-20

).

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.14-16

).

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Replace or add engine coolant.

STEP 3. MUT-III actuator test

• Item 21: Fan controller

OK: Fan motor rotating

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Check fan control relay system (Refer to 
Inspection Procedure 24 

P.13A-340

).

STEP 4. MUT-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 
system (Refer to Code No. P0115 

P.13A-37

).

STEP 5. Check thermostat.

• Check thermostat (Refer to GROUP 14 − 

Thermostat 

− Thermostat Inspection 

P.14-21

).

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.

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-318

Inspection Procedure 21: Abnormal Rotation of Fan Motor

OPERATION

• The control (duty) signal is inputted to the fan 

controller (terminal No. 2) from the engine-ECU 
<M/T> or engine-A/T-ECU <A/T> (terminal No. 
17).

FUNCTION

• The engine-ECU <M/T> or engine-A/T-ECU 

<A/T> inputs a duty signal suitable for the engine 
coolant temperature, vehicle speed and A/C 
switch position to the fan controller. In response 
to the signal, the fan controller controls the 
rotating speeds of the radiator fan and A/C 
condenser fan (The fan speed becomes higher 
as the average voltage of the terminal comes 
nearer to 5V).

PROBABLE CAUSE

• Failed fan controller

• Open/short circuit in fan controller circuit or loose 

connector contact

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

AK305577

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2

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5

6 7 8 9

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20

21 22

232425

2627

10111213

14 15

16 1718

19

1 2 3

C-110

(MU803802)

AB

Fan controller

Fan 
control
circuit

      A-26
(MU802322)

2

L-W

L-W

8

A-16

17

Fan controller (Radiator fan, A/C condensor fan) circuit

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

Engine-ECU <M/T> or
engine-A/T-ECU <A/T>