Mitsubishi Montero Sport (2004+). Manual - part 239

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-369

STEP 7. Check for open circuit or short circuit to ground 
between left bank heated oxygen sensor (rear) connector 
E-48 (terminal No. 3) and PCM connector C-89 (terminal 
No. 26).

NOTE: Check harness after checking intermediate connector 
C-79 and E-45. If intermediate connectors are damaged, repair 
or replace them. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. Then go to Step 12.

Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 12.
NO :  Repair it. Then go to Step 12.

AK200498

1

2

3

4

E-48(B)

AB

CONNECTOR: E-48

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

AK103914

2

3

4

5

6

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8

9

11

12

13

14

15

16

17

18

19

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30

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22

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25

26

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32

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34

35

1

10

AB

CONNECTOR: C-89

C-89(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-370

STEP 8. Check connector C-89 at PCM for damage.
Q: Is the 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 12.

STEP 9. Check for harness damage between MFI relay 
connector C-59 (terminal No. 1) and left bank heated 
oxygen sensor (rear) connector E-48 (terminal No. 1).

AK103914

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

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25

26

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32

33

34

35

1

10

AB

CONNECTOR: C-89

C-89(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK200023

2 1

3

4

CONNECTOR: C-59

AB

C-59

HARNESS 
CONNECTOR:
COMPONENT 
SIDE

AK200498

1

2

3

4

E-48(B)

AB

CONNECTOR: E-48

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-371

NOTE: Check harness after checking intermediate connectors 
C-14, C79 and E-45.
If intermediate connectors C-14, C79 and E-45 are damaged, 
repair or replace them.
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step12.
Q: Is the harness wire in good condition?

YES : Go to Step 10.
NO :  Repair it. Then go to Step 12.

STEP 10. Check for harness damage between left bank 
heated oxygen sensor (rear) connector E-48 (terminal No. 
3) and PCM connector C-89 (terminal No. 26).

AK200498

1

2

3

4

E-48(B)

AB

CONNECTOR: E-48

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

AK103914

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

CONNECTOR: C-89

C-89(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-372

NOTE: Check harness after checking intermediate connectors 
C-14, C79 and E-45.
If intermediate connectors C79 and E-45 are damaged, repair 
or replace them.
Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

. 

Then go to Step12.
Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO :  Repair it. Then go to Step 12.

STEP 11. Retest the system.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function  OBD-II Drive Cycle 

− Procedure 6 − 

Other Monitor 

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0161 set?

YES : Replace the PCM. Then go to Step 12.
NO :  It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

P.00-7

.

STEP 12. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13A-4

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0161 set

YES : Repeat the troubleshooting.
NO :  The procedure is complete.

DTC P0171: System too Lean (bank 1)

.

Fuel Trim Circuit

• Refer to DTC P0201 − P0206, Injector Cir-

cuit.

P.13A-428

.

CIRCUIT OPERATION

• Refer to DTC P0201 − P0206, Injector Cir-

cuit.

P.13A-428

.

TECHNICAL DESCRIPTION

• If a malfunction occurs in the fuel system, the fuel 

trim value becomes too large.

• The PCM checks whether the fuel trim value is 

within a specified range.

.

DESCRIPTIONS OF MONITOR METHODS
Right bank air/fuel learning value (long time fuel trim) 

and air/fuel feedback integral value (short time 
fuel trim) are too lean.

.

MONITOR EXECUTION
Continuous

.

MONITOR EXECUTION CONDITIONS (Other 
monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Misfire monitor

Sensor (The sensor below is determined to be 

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.