Mitsubishi Montero (2004+). Manual - part 356

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-911

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

AK201380AE

MFI RELAY SIDE
CONNECTOR

1

2

3

4

AK201381AE

MFI RELAY SIDE
CONNECTOR

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-912

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

AK201382AE

B-22X HARNESS
CONNECTOR:
COMPONENT SIDE

AK200939

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58

50

51

AB

CONNECTOR: D-133

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-133(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-913

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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58

50

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AB

CONNECTOR: D-133

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-133(GR)

AK201375

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D-133 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK201375AB

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MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-914

STEP 6. Measure the backup power supply voltage at PCM 
harness side connector D-133.
(1) Disconnect the connector D-133 and measure at the 

harness side.

(2) Measure the voltage between terminal No.58 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 7.
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 PCM connector D-133 (terminal 
No. 58). Then confirm that the malfunction symptom 
is eliminated.

AK200939

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58

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AB

CONNECTOR: D-133

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-133(GR)

AK201376

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D-133 HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK201376AB

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