Mitsubishi Montero Sport (2004+). Manual - part 234

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-349

DTC P0158: Heated Oxygen Sensor Circuit High Voltage (bank 2, sensor 2)

AK303392

Left Bank Heated Oxygen Sensor (rear) Circuit

BL

ACK

BL

ACK

BL

ACK

BL

ACK

WHITE

BL

ACK

BL

ACK

BL

ACK

WHITE

WHITE

BL

ACK

-RED

BL

ACK

-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

73

57

19

5

16

10

12

8

2

7

4

2

3

1

C-91

C-90

FROM MFI RELAY

TO PCM

LEFT 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)

1 2
3 4

E-48
MU802605

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-350

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 73) from the output terminal (terminal 
No. 4) of the left bank heated oxygen sensor 
(rear).

• Terminal No. 2 of the left bank heated oxygen 

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

.

TECHNICAL DESCRIPTION

• The output signal of the left bank heated oxygen 

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

• The PCM checks for an open circuit in the left 

bank heated oxygen sensor (rear) output line.

.

DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (rear) output voltage 

is over specified range.

AK200497

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

E-48(B)

AB

CONNECTOR: E-48

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)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-351

.

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

.

Check Conditions

• 2 minutes or more have passed since the starting 

sequence was completed.

Judgment Criteria

• Left bank heated oxygen sensor (rear) output 

voltage has continued to be 1.2 volts or higher for 
2 seconds.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-4

.

.

TROUBLESHOOTING HINTS (The most likely 

causes for this code to be set are:)

• Open circuit in left bank heated oxygen sensor 

(rear) output line.

• Connector damage.

• PCM failed.

START

END

NO

NO

YES

YES

MALFUNCTION

GOOD

2secs HAVE PASSED?

OUTPUT VOLTAGE > 1.2V

NO

YES

MONITORING

CONDITIONS

AK301441

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-352

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I

• MB991827: USB Cable

• MB991911: Main Harness B

STEP 1. Check harness connector E-48 at left bank heated 
oxygen sensor (rear) and harness connector C-91 at PCM 
for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 3.

AK200498

1

2

3

4

E-48(B)

AB

CONNECTOR: E-48

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

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