Mitsubishi Montero Sport (2004+). Manual - part 211

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-257

STEP 3. 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 P0138 set?

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-258

DTC P0139: Heated Oxygen Sensor Circuit Slow Response (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-259

.

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.

.

AK103912AB

CONNECTOR: C-71

C-71

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)

AK200018 AB

CONNECTOR: E-44

E-44

AK103911AC

CONNECTOR: C-79

C-79

AK200018 AC

CONNECTOR: E-45

E-45(B)

AK200491

E-47(GR)

AB

CONNECTOR: E-47

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-260

DESCRIPTIONS OF MONITOR METHODS
Right bank heated oxygen sensor (rear) output volt-

age does not change during specified go/stop 
operations including fuel cut are repeated.

.

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)

• Heated oxygen sensor heater (front) monitor

• Heated oxygen sensor heater (rear) monitor

• Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be 

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

.

DTC SET CONDITIONS

Logic Flow Chart

.

END

YES

NO

NO

NO

START

MONITORING

CONDITION

YES

MALFUNCTION

GOOD

F1: COUNTER OF A DRIVING STATE.
F2: COUNTER OF A STOP STATE.

OUTPUT VOLTAGE 

CHANGE < 0.313 V

GO/STOP OPERATION

FOR SPECIFIED TIMES

YES

AK301442