Mitsubishi Montero (2004+). Manual - part 355

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-907

DIAGNOSIS

STEP 1. Check harness connector D-132 at PCM for 
damage.
Q: Is the harness connector in good condition?

YES :  Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then confirm that the 

malfunction symptom is eliminated.

STEP 2. Measure the output voltage at PCM harness side 
connector D-132.
(1) Disconnect the connector D-132 and measure at the 

harness side.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal No. 17 and ground.

• Voltage should be battery positive voltage.

(4) Check the condenser fan condition.

• When the terminal No. 17 is disconnected, the fan 

should stop.

• When the terminal No. 17 is grounded by the jumper 

cable, the fan should run.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage and fan condition normal?

YES :  Replace the PCM. Then confirm that the malfunction 

symptom is eliminated.

NO :  Refer to GROUP 55, Introduction To Heater, Air 

Conditioning And Ventilation Diagnosis 

P.55A-5

.

AK200938

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13

AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

AK200938

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AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

AK201374

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D-132 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK201374AB

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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-908

INSPECTION PROCEDURE 28: Power supply system and ignition switch-IG system.

WHITE-

BLA

C

K

WHITE-

BLA

CK

WHITE-

BLA

CK

BLA

CK

WHITE-BLA

CK

BLA

CK

AK302912

RED

WHITE-BLUE

RED

RED

BLUE-BLA

CK

BLUE-BLA

CK

BLUE-BLA

CK

1

6

4

1

3

5

4

2

3

2

4 5 6

1

D-208

MU801331

8

2

3

2

1

8

5 6 7

4

D-221

(MU801866)

R

IG2

ST

LOCK

ACC

IG1

3

4 5 6

1 2

D-204

2

IGNITION SWITCH

4

1 2
3

B-22X

2

POWERTRAIN
CONTROL
MODULE (PCM)

3

58

FUSIBLE
LINK (5)

5

57

34

50

POWER
SUPPLY

BATTERY
BACKUP

42

43

33

MFI RELAY

1
5

7 8

3 4
9 10

2
6

D-14

MU801335

1

12

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20 21 22

27 28 29 30 31 32 33

10 11

D-116

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17

18

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3 4

7 8

19 20

30 31

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24

33 34 35

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32

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28

38

25

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22

1

5

E-111

Power Supply and Ignition Switch-IG Circuit

31

35363738394041 42 43
444546474849

50 51

5253

545556

57 58

32

33 34

D-133

(MU803803)

A-03

(MU802611)

1 2 3 4 5 6
7 8 9 10 11 12

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-909

AK201038

CONNECTOR: D-133

AC

PCM

D-133(GR)

AK201045

D-204

AB

CONNECTOR: D-204

AK201041AD

CONNECTOR: D-208

D-208

AK201046

A-03(B)

AB

CONNECTOR: A-03

AK201039

MFI RELAY

B-22X

AB

CONNECTOR: B-22X

AK201049

CONNECTOR: D-116

D-116

AC

AK201294

D-221

AB

CONNECTOR: D-221

AK201043

E-111

AB

CONNECTOR: E-111

AK201049

D-14

AB

CONNECTOR: D-14

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-910

.

CIRCUIT OPERATION

• Battery positive voltage is applied to the MFI 

relay (terminal No. 2, No. 3).

• When the ignition switch is turned to the "ON" 

position, the battery positive voltage is applied to 
the PCM (terminal No. 50).
When the battery positive voltage is applied, the 
PCM turns the power transistor in the PCM "ON" 
and grounds the MFI relay coil, with this, the MFI 
relay turns "ON" and the battery positive voltage 
is supplied to the PCM (terminal No. 34, No. 43) 
from the MFI relay (terminal No. 1).

• Battery positive voltage is constantly supplied to 

the PCM (terminal No. 58) as the backup power.

• The or PCM (terminal No. 33, No. 42) is 

grounded to the vehicle body.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are: ) 

• Malfunction of the ignition switch.

• Malfunction of the MFI relay.

• Improper connector contact, open circuit or 

short-circuited harness wire.

• Disconnected PCM ground wire.

• Malfunction of the PCM.

DIAGNOSIS

STEP 1. Check harness connector B-22X at MFI relay for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then confirm that the 

malfunction symptom is eliminated.

AK200951

2 1

3

4

B-22X

AB

CONNECTOR: B-22X

HARNESS 
CONNECTOR: 
COMPONENT SIDE