Mitsubishi Montero (2004+). Manual - part 269

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-563

STEP 1. Using scan tool MB991958, check data list item 73: 
Fuel Tank Differential Pressure Sensor.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.

(2) Disconnect hose F from the evaporative emission canister 

side, and plug the hose.

(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991958 to the data reading mode.

Item 73, Fuel Tank Differential Pressure Sensor.

• The fuel tank pressures reading on the scan tool 

should be 

−1.5 to 1.5 kPa (−0.443 to 0.443 inHg).

(6) Connect an evaporative emission system pressure pump to 

the fuel tank filler tube and pressurize the fuel tank.

• The fuel tank pressure reading should increase.

(7) Disconnect an evaporative emission system pressure pump 

and connect hose F.

(8) Turn the ignition switch to the "LOCK" (OFF) position and 

disconnect scan tool MB991958.

Q: Is the fuel tank pressure between 

−1.5 and 1.5 kPa 

(

−0.443 and 0.443 inHg)?

YES : It can be assumed that this malfunction is intermittent. 

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

− How to 

Cope with Intermittent Malfunction 

P.00-6

). Go to 

Step 15.

NO :  Go to Step 2.

AC306409AF

MB991911

MB991824

MB991827

AC102602 AC

HOSE F

ACX01358

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-564

STEP 2. Measure the signal voltage at fuel tank differential 
pressure sensor connector G-05.
(1) Tumble the second seat.
(2) Remove the service hole cover (upper) and packing.
(3) Remove the service hole cover (lower) and packing.
(4) Disconnect fuel tank differential pressure sensor connector 

G-05.

(5) Connect special tool MB991658 between fuel tank 

differential pressure sensor connector G-05 terminals 1, 2 
and 3.

(6) Turn the ignition switch to the "ON" position.
(7) Remove the fuel cap.
(8) Measure the voltage between fuel tank differential pressure 

sensor connector G-05 terminal 1 and ground.

• The voltage should measure between 2.0 and 3.0 volts.

(9) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 2.0 and 3.0 volts?

YES : Go to Step 10.
NO :  Go to Step 3.

STEP 3. Measure the 5-volt reference signal at fuel tank 
differential pressure sensor connector G-05.
(1) Disconnect fuel tank differential pressure sensor connector 

G-05.

(2) Connect special tool MB991658 between fuel tank 

differential pressure sensor connector G-05 terminals 1, 2 
and 3.

(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between fuel tank differential pressure 

sensor connector G-05 terminal 3 and ground.

• The voltage should measure between 4.9 and 5.1 volts.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?

YES : Go to Step 8.
NO :  Go to Step 4.

ACX00218

CONNECTOR : G-05

AS

G-05 (B)

SERVICE HOLE (UPPER)

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

1

2

3

SERVICE HOLE (LOWER)

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL 
PRESSURE SENSOR

ACX00218

CONNECTOR : G-05

AR

G-05 (B)

SECOND SEAT UNDER
SERVICE HOLE

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

1

2

3

AC002081AB

MB991658

FUEL TANK DIFFERENTIAL 
PRESSURE SENSOR

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-565

STEP 4. Measure the 5-volt reference signal at PCM 
connector D-135 by backprobing.
(1) Do not disconnect PCM connector D-135.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between PCM connector D-135 

terminal 97 and ground by backprobing.

• The voltage should measure between 4.9 and 5.1 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?

YES : Go to Step 6.
NO :  Go to Step 5.

STEP 5. Check PCM connector D-135 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 14.
NO :  Repair or replace the faulty component. (Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

). Go to Step 15.

AC203993

CONNECTOR: D-135

AC

D-135 (GR)

PCM

94

93

95

96 97 98 99 100

92

91

101 102 103

104

105 106

107 108 109

110 111 112

113 114

115 116 117

118 119 120

AC204160 AB

D-135 HARNESS CONNECTOR:
HARNESS SIDE

AC203997

CONNECTOR: D-135

AB

D-135 (GR)

PCM

D-135 HARNESS CONNECTOR:
HARNESS SIDE

94

93

95

96 97 98 99 100

92

91

101 102103

104

105 106

107 108 109

110 111 112

113 114

115 116 117

118 119 120

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-566

STEP 6. Check intermediate connectors D-112, E-111 and 
F-07, and fuel tank differential pressure sensor connector 
G-05 for loose, corroded or damaged terminals, or 
terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 7.
NO :  Repair or replace the faulty component. (Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

). Go to Step 15.

AC203998

CONNECTOR: D-112

AC

D-112

D-112 HARNESS
CONNECTOR:
COMPONENT SIDE

38

28

16

33

22

10

31

19

7

1

18

30

29

17

5

6

21

20

32

8

2

9

25

13

3

24

23

34 35

11 12

27

26

36 37

14

4

15

AC203999

CONNECTOR: E-111

AC

E-111

E-111 HARNESS
CONNECTOR:
COMPONENT SIDE

38

12 13

11

26

14

1

20

6

23 24 25

37

31

36

30

10

9

21 22

35

8

7

34

17

29

18 19

5

4

15 16

33

28

32

27

3

2

AC204000

CONNECTOR: F-07

AC

F-07 (B)

F-07 HARNESS
CONNECTOR:
COMPONENT SIDE

8

4

3

2

1
5 6 7

ACX00218

CONNECTOR : G-05

AR

G-05 (B)

SECOND SEAT UNDER
SERVICE HOLE

G-05 HARNESS
CONNECTOR:
COMPONENT SIDE

1

2

3