Mitsubishi Montero Sport (2004+). Manual - part 207

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-241

STEP 10. Check the right bank heated oxygen sensor 
(rear).
(1) Disconnect the right bank heated oxygen sensor (rear) 

connector E-47 and connect test harness special tool, 
MB991316, to the connector on the right bank heated 
oxygen sensor (front) side.

(2) Warm up the engine until engine coolant 80

°C (176°F) or 

higher.

(3) Perform a tracing for 5 minutes or more with the engine 

speed of 4,500 r/min.

(4) Connect a digital volt meter between terminal No. 2 (black 

clip) and terminal No. 4 (white clip).

(5) While repeatedly revving the engine, measure the right 

bank heated oxygen sensor (rear) output voltage.

Standard value: 0.6 

− 1.0 volt

CAUTION

• Be very careful when connecting the jumper wire; 

incorrect connection can damage the oxygen sensor.

• Be careful the heater is broken when voltage of beyond 

12 volts is applied to the oxygen sensor heater.
NOTE: If the sufficiently high temperature (of approximate 
400

°

C or more) is not reached although the oxygen sensor 

is normal, the output voltage would be possibly low 
although the rich air-fuel ratio. Therefore, if the output volt-
age is low, use a jumper wire to connect the terminal No.2 
and the terminal No. 1 of the oxygen sensor with a (+) termi-
nal and (-) terminal of 12 volts power supply respectively, 
then check again.

Q: Is the voltage at the standard value?

YES : Replace the PCM. Then go to Step 11.
NO :  Replace the right bank heated oxygen sensor (rear). 

Then go to Step 11.

AK200492

1

2

3

4

E-47(GR)

AB

CONNECTOR: E-47

HARNESS 
CONNECTOR: 
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AKX01624

HEATED
OXYGEN
SENSOR
COMPONENT
SIDE
CONNECTOR

MB991316

WHITE

BLACK

AN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-242

STEP 11. 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 P0136 set?

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-243

DTC P0137: Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 2)

AK000458

Right Bank Heated Oxygen Sensor (rear) Circuit

1 2
3 4

BLA

CK

BLA

CK

BLA

CK

BLA

CK

WHITE

BLA

CK

BLA

CK

BLA

CK

WHITE

WHITE

BLA

CK-RED

BLA

CK-RED

POWERTRAIN CONTROL MODULE (PCM)

1

10

15

2

11

3

12

4

13 14

5

16

6

17

7

18

8

19

9

20

E-44

E-47
MU802665

74

57

20

2

11

20

12

4

5

13

4

2

3

1

C-91

C-90

FROM MFI RELAY

TO PCM

RIGHT BANK HEATED
OXYGEN SENSOR (REAR)

1

10

15

2

11

3

12

4

13 14

5

16

6

17

7

18

8

19

9

20

E-45

E-45

47

41

42 43

48 49 50 51 52 53 54 55 56 57

46

45

44

58

59

60 61 62 63

64 65 66

C-90
(MU803781)

1

10

2 3 4 5 6 7 8 9

11

12 13 14 15 16 17 18 19 20 21 22

23 24 25 26 27 28 29 30 31 32 33

C-71

71

76

77

72 73 74

75

79 80

78

81

87 88

89

91

90

92

97

98

82

93

83

94

84 85

95

86

96

C-91
(MU803782)

6

10

2

7

8

3 4 5

9

11 12 13

1

C-79
MU801553

JOINT
CONNECTOR (4)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-244

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 74) from the output terminal (terminal 
No. 4) of the right bank heated oxygen sensor 
(rear).

• Terminal No. 2 of the right bank heated oxygen 

sensor (rear) is grounded with PCM (terminal No. 
57).

.

TECHNICAL DESCRIPTION

• The output signal of the right bank heated oxygen 

sensor (front) is compensated by the output sig-
nal of the right bank heated oxygen sensor (rear).

• The PCM checks for an open circuit in the right 

bank heated oxygen sensor (rear) output line.

.

AK200491

E-47(GR)

AB

CONNECTOR: E-47

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)

AK200018 AB

CONNECTOR: E-44

E-44

AK103912AB

CONNECTOR: C-71

C-71

AK103911AC

CONNECTOR: C-79

C-79

AK200018 AC

CONNECTOR: E-45

E-45(B)