Mitsubishi Montero Sport (2004+). Manual - part 220

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-293

STEP 3. Check connector A-09 at left bank heated oxygen 
sensor (front) and connector C-91 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 5.

AK200496

1

2

3

4

A-09(GR)

AB

CONNECTOR: A-09

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (FRONT)

AK104028

98

78

71

88

89

76

77

72
79
91

73
80

74

75

81
92

82

83

93

84

85

94

86

87

95

96

90

97

AB

CONNECTOR: C-91

C-91(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-294

STEP 4. Check for short circuit to ground and harness 
damage between left bank heated oxygen sensor (front) 
connector A-09 (terminal No. 4) and PCM connector C-91 
(terminal No. 71).
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 5.
NO :  Repair it. Then go to Step 5.

STEP 5. 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 P0151 set?

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

AK200496

1

2

3

4

A-09(GR)

AB

CONNECTOR: A-09

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (FRONT)

AK104028

98

78

71

88

89

76

77

72
79
91

73
80

74

75

81
92

82

83

93

84

85

94

86

87

95

96

90

97

AB

CONNECTOR: C-91

C-91(GR)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-295

DTC P0152: Heated Oxygen Sensor Circuit High Voltage (bank 2, sensor 1)

AK000490

Left Bank Heated Oxygen Sensor (front) Circuit

WHITE

BL

ACK

RED

BL

ACK

BL

ACK

-RED

C-91

POWERTRAIN CONTROL MODULE (PCM)

FROM MFI RELAY

TO PCM

LEFT BANK HEATED OXYGEN SENSOR (FRONT)

4

71

57

C-90

12

32

2

3

1

22

33

1 2
3 4

A-09
MU802665

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)

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

JOINT
CONNECTOR (4)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-296

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 71) from the output terminal (terminal 
4) of the left bank heated oxygen sensor (front).

• Terminal No. 2 of the left bank heated oxygen 

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

.

TECHNICAL DESCRIPTION

• The left bank heated oxygen sensor (front) 

detects the concentration of oxygen in the 
exhaust gas; it converts that data to voltage, and 
sends it to the PCM.

• When the left bank heated oxygen sensor (front) 

begins to deteriorate, the heated oxygen sensor 
signal response deteriorates also.

• The PCM varies the air/fuel mixture to make it 

leaner and richer, and checks the response 
speed of the left bank heated oxygen sensor 
(front). In addition, the PCM also checks for an 
open circuit in the left bank heated oxygen sensor 
(front) output line.

.

DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (front) output volt-

age is over specified range.

.

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

• Misfire monitor

• Fuel system monitor

AK200495

LEFT BANK
HEATED OXYGEN
SENSOR (FRONT)

A-09(GR)

AB

CONNECTOR: A-09

AK103912AB

CONNECTOR: C-71

C-71

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)