Mitsubishi Montero (2002-2004). Manual - part 757

TSB Revision

SYMPTOM PROCEDURES

13Ad-77

.

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

TSB Revision

SYMPTOM PROCEDURES

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STEP 2. Check the MFI relay.
(1) Remove the MFI relay.

(2) Check for continuity between the MFI relay terminal No. 2 

and No. 4.

• There should be continuity (approximately 70 ohms)

(3) Use jumper wires to connect MFI relay terminal No. 2 to the 

positive battery terminal and terminal No. 4 to the negative 
battery terminal.

(4) Check the continuity between the MFI relay terminal No. 1 

and No. 3 while connecting and disconnecting the jumper 
wire at the negative battery terminal.

• Should be less than 2 ohms. (Negative battery terminal 

connected)

• Should be open loop. (Negative battery terminal discon-

nected)

(5)  Install the MFI relay.
Q: Is the resistance normal?

YES : Go to Step 3.
NO :  Replace the MFI relay. Then confirm that the 

malfunction symptom is eliminated.

AK200951

2 1

3

4

B-22X

AB

CONNECTOR: B-22X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

4

AK201380

MFI RELAY SIDE
CONNECTOR

AK201380AD

1

2

3

4

AK201381

MFI RELAY SIDE
CONNECTOR

AK201381AD

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SYMPTOM PROCEDURES

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STEP 3. Measure the power supply voltage at MFI relay 
harness side connector B-22X.
(1) Disconnect the connector B-22X and measure at the 

harness side.

(2) Measure the voltage between terminal No. 2, No. 3 and 

ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 4.
NO :  Check harness connector A-03 at intermediate 

connector for damage, and repair or replace as 
required. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. If intermediate connector A-03 is 

in good condition, repair an open circuit between 
fusible link (5) and MFI relay connector B-22X 
(terminal No. 2, No. 3). Then confirm that the 
malfunction symptom is eliminated.

STEP 4. Check harness connector D-133 at PCM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 5.
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

2 1

3

4

AK201382

B-22X HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK201382AD

AK200939

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52

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55

56

57

58

50

51

AB

CONNECTOR: D-133

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-133(GR)

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SYMPTOM PROCEDURES

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STEP 5. Measure the ignition switch-IG signal voltage at 
PCM harness side connector D-133.
(1) Disconnect the connector D-133 and measure at the 

harness side.

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

(3) Measure the voltage between terminal No. 50 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 6.
NO :  Check harness connector E-111, D-02, D-28 at 

intermediate connector for damage, and repair or 
replace as required. Refer to GROUP 00E, Harness 
Connector Inspection 

P.00E-2

. If intermediate 

connector E-111, D-02, D-28 are in good condition, 
repair it because of open circuit between ignition 
switch connector D-204 (terminal No. 2) and PCM 
connector D-133 (terminal No. 50). Then confirm that 
the malfunction symptom is eliminated.

AK200939

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52

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56

57

58

50

51

AB

CONNECTOR: D-133

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-133(GR)

AK201375

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58

50

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D-133 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK201375AB

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