Mitsubishi Montero (2004+). Manual - part 235

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-427

 STEP 6. Measure the power supply voltage at injector 
intermediate connector B-44.
(1) Disconnect the connector B-44 and measure at the female 

connector relay side.

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

(3) Measure the voltage between terminal No. 8 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 8.
NO :  Go to Step 7.

STEP 7. Check harness connector B-22X at MFI relay for 
damage.
Q: Is the harness connector in good condition?

YES : Repair harness wire between MFI relay connector 

B-22X (terminal No. 1) and intermediate connector 
B-44 (terminal No. 8) because of open circuit or short 
circuit to ground or harness damage. Then go to Step 
17.

NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 17.

AK200949

3

4

7

8

1

2

5

6

B-44(B)

CONNECTOR: B-44

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AKX01493

B-44 FAMALE
SIDE CONNECTOR

1

2

3

4

5

6

7

8

AB

AK200951

2 1

3

4

B-22X

AB

CONNECTOR: B-22X

HARNESS 
CONNECTOR: 
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-428

STEP 8. Check harness connector D-132 at PCM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 9.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 17.

STEP 9. Check for open circuit and short circuit to ground 
and harness damage between injector intermediate 
connector and PCM connector.

a. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 3) and PCM connector D-132 (ter-
minal No. 1) at No. 1 cylinder injector.

b. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 2) and PCM connector D-132 (ter-
minal No. 5) at No. 2 cylinder injector.

c. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 1) and PCM connector D-132 (ter-
minal No. 14) at No. 3 cylinder injector.

d. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 7) and PCM connector D-132 (ter-
minal No. 21) at No. 4 cylinder injector.

e. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 6) and PCM connector D-132 (ter-
minal No. 2) at No. 5 cylinder injector.

f. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 5) and PCM connector D-132 (ter-
minal No. 6) at No. 6 cylinder injector.

Q: Is the harness wire in good condition?

YES : Go to Step 10.
NO :  Repair it. Then go to Step 17.

AK200938

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9

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10

14

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21

22

23

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25

26

27

11

12

13

AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

AK200949

3

4

7

8

1

2

5

6

B-44(B)

CONNECTOR: B-44

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK200938

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5

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27

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13

AB

CONNECTOR: D-132

HARNESS CONNECTOR: 
COMPONENT SIDE

PCM

D-132(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-429

STEP 10. Using the oscilloscope, check the injector.
(1) Disconnect the injector intermediate connector B-44 and 

connect the test harness special tool (MB998474) in 
between.

(2) Connect the oscilloscope probe to each injector 

intermediate connector terminal to oscilloscope each 
cylinder:

• Terminal No. 3 (green clip) at No. 1 cylinder injector.

• Terminal No. 2 (white clip) at No. 2 cylinder injector.

• Terminal No. 1 (blue clip) at No. 3 cylinder injector.

• Terminal No. 7 (yellow clip) at No. 4 cylinder injector.

• Terminal No. 6 (red clip) at No. 5 cylinder injector.

• Terminal No. 5 (black clip) at No. 6 cylinder injector.

NOTE: When measuring with the PCM side connector, con-
nect an oscilloscope probe to the each of the following ter-
minals.

.

•

PCM terminal No. 1 at No. 1 cylinder injector.

•

PCM terminal No. 5 at No. 2 cylinder injector.

•

PCM terminal No. 14 at No. 3 cylinder injector.

•

PCM terminal No. 21 at No. 4 cylinder injector.

•

PCM terminal No. 2 at No. 5 cylinder injector.

•

PCM terminal No. 6 at No. 6 cylinder injector.

(3) Start the engine and run at idle.

(4) Measure the waveform.

• The waveform should show a normal pattern similar to 

the illustration.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?

YES : Go to Step 13.
NO :  Go to Step 11.

AK200949

3

4

7

8

1

2

5

6

B-44(B)

CONNECTOR: B-44

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK102982 AB

OSCILLOSCOPE

INJECTOR
INTERMEDIATE
CONNECTOR

MD998474

1 2 3 4

5 6 7 8

AKX01557 AB

A

NORMAL  WAVEFORM

A:INJECTOR DRIVE TIME

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-430

STEP 11. Check the injector connector for damage.

a. Check harness connector B-01 at No. 1 cylinder injector.
b. Check harness connector B-33 at No. 2 cylinder injector.

c. Check harness connector B-02 at No. 3 cylinder injector.

d. Check harness connector B-35 at No. 4 cylinder injector.
e. Check harness connector B-03 at No. 5 cylinder injector.

f. Check harness connector B-11 at No. 6 cylinder injector.

Q: Is the harness connector in good condition?

YES : Go to Step 12.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 17.

STEP 12. Check for short circuit to ground between 
injector intermediate connector and injector connector.

a. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-01 
(terminal No. 1) and injector connector B-01 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 3) at 
No. 1 cylinder injector.

b. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-33 
(terminal No. 1) and injector connector B-33 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 2) at 
No. 2 cylinder injector.

c. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-02 
(terminal No. 1) and injector connector B-02 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 1) at 
No. 3 cylinder injector.

d. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-35 
(terminal No. 1) and injector connector B-35 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 7) at 
No. 4 cylinder injector.

e. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-03 
(terminal No. 1) and injector connector B-03 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 6) at 
No. 5 cylinder injector.

f. Check the harness wire between injector intermediate con-

nector B-44 (terminal No. 8) and injector connector B-11 
(terminal No. 1) and injector connector B-11 (terminal No. 2) 
and injector intermediate connector B-44 (terminal No. 5) at 
No. 6 cylinder injector.

Q: Is the harness wire in good condition?

YES : Replace the PCM Then go to Step 17.
NO :  Repair it. Then go to Step 17.

AK200960

1

2

B-03(GR)

B-11(GR)

B-35(GR)

B-33(GR)

B-02(GR)

B-01(GR)

CONNECTORS: B-01, B-02, B-03, B-11, 

B-33, B-35

AB

HARNESS CONNECTOR: 
COMPONENT SIDE

AK200949

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8

1

2

5

6

B-44(B)

CONNECTOR: B-44

AB

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AK200960

1

2

B-03(GR)

B-11(GR)

B-35(GR)

B-33(GR)

B-02(GR)

B-01(GR)

CONNECTORS: B-01, B-02, B-03, B-11, 

B-33, B-35

AB

HARNESS CONNECTOR: 
COMPONENT SIDE