Mitsubishi Grandis. Manual — part 695

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-31

PROBABLE CAUSE

• Failed intake air temperature sensor

• Open/short circuit in intake air temperature

sensor circuit or loose connector contact

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. MUT-III data list

• Refer to Data List Reference Table

P.13A-363

.

a. Item 13: Intake air temperature sensor

OK: At ambient temperature (atmospheric
temperature) or equivalent.

Q: Is the check result normal?

YES :

Intermittent malfunction (Refer to GROUP

00

− How to Use

Troubleshooting/Inspection Service Points

P.00-5

).

NO :

Go to Step 2 .

STEP 2. Connector check: B-106 air flow sensor
connector

Q: Is the check result normal?

YES :

Go to Step 3 .

NO :

Repair or replace.

STEP 3. Check intake air temperature sensor
itself.

• Check intake air temperature sensor itself (Refer

to

P.13A-389

).

Q: Is the check result normal?

YES :

Go to Step 4 .

NO :

Replace air flow sensor.

STEP 4. Perform resistance measurement at
B-106 air flow sensor connector.

• Disconnect connector, and measure at harness

side.

• Voltage between terminal No. 4 and earth.

OK: 2

Ω or less

Q: Is the check result normal?

YES :

Go to Step 8 .

NO :

Go to Step 5 .

STEP 5. Connector check: C-113 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.

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-32

STEP 6. Check harness between B-106 (terminal
No. 4) air flow sensor connector and C-113
(terminal No. 96) engine-ECU <M/T> connector or
engine-A/T-ECU <A/T> connector.

NOTE: Before checking harness, check intermediate
connector C-116, and repair if necessary.

• Check earthing line for open circuit and damage.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair.

STEP 7. MUT-III data list

• Item No. 13: Intake air temperature sensor

OK: At ambient temperature (atmospheric
temperature) or equivalent.

Q: Is the check result normal?

YES :

Intermittent malfunction (Refer to GROUP

00

− How to Use

Troubleshooting/Inspection Service Points

P.00-5

).

NO :

Replace engine-ECU <M/T> or
engine-A/T-ECU <A/T>.

STEP 8. Perform voltage measurement at B-106
air flow sensor connector.

• Disconnect connector, and measure at harness

side.

• Ignition switch: ON

• Voltage between terminal No. 1 and earth.

OK: 4.5

− 4.9 V

Q: Is the check result normal?

YES :

Replace engine-ECU <M/T> or

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

NO :

Go to Step 9 .

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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Harness side connector

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-33

STEP 9. Perform voltage measurement at C-113
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.

• Disconnect B-106 air flow sensor connector.

• Ignition switch: ON

• Voltage between terminal No. 99 and earth.

OK: 4.5

− 4.9 V

Q: Is the check result normal?

YES :

Go to Step 10 .

NO :

Go to Step 11 .

STEP 10. Connector check: C-113 engine-ECU
<M/T> connector or engine-A/T-ECU <A/T>
connector

Q: Is the check result normal?

YES :

Check and repair harness between B-106

(terminal No. 1) air flow sensor connector
and C-113 (terminal No. 99) engine-ECU
<M/T> connector or engine-A/T-ECU <A/T>
connector.

• Check output line for open circuit.

NO :

Repair or replace.

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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120

Harness side connector

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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Harness side connector

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-34

STEP 11. Connector check: C-113 engine-ECU
<M/T> connector or engine-A/T-ECU <A/T>
connector

Q: Is the check result normal?

YES :

Go to Step 12 .

NO :

Repair or replace.

STEP 12. Check harness between B-106 (terminal
No. 1) air flow sensor connector and C-113
(terminal No. 99) engine-ECU <M/T> connector or
engine-A/T-ECU <A/T> connector.

• Check output line for short circuit.

Q: Is the check result normal?

YES :

Go to Step 7 .

NO :

Repair.

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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Harness side connector

AK300969

2

1

3

4

Harness side connector

AC

Connector: B-106

B-106 (GR)

AK305616AB

Connector: C-113

<L.H. drive vehicles>

<R.H. drive vehicles>

C-113 (GR)

C-113 (GR)

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Harness side connector