Mitsubishi Montero Sport (2004+). Manual — part 197

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-201

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 connector A-07 at right bank heated
oxygen sensor (front) and connector C-91 at PCM for
damage.
Q: Is the 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.

AK200490

1

2

3

4

A-07(B)

AB

CONNECTOR: A-07

HARNESS
CONNECTOR:
COMPONENT SIDE

RIGHT 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-202

STEP 2. Check for short circuit to power supply between
right bank heated oxygen sensor (front) connector A-07
(terminal No. 4) and PCM connector C-91 (terminal No. 72).
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 3.
NO : Repair it. Then go to Step 3.

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 P0132 set?

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

AK200490

1

2

3

4

A-07(B)

AB

CONNECTOR: A-07

HARNESS
CONNECTOR:
COMPONENT SIDE

RIGHT 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-203

DTC P0133: Heated Oxygen Sensor Circuit Slow Response (bank 1 sensor 1)

BLA

CK

BLA

CK

WHITE

BLA

CK-RED

AK000444

Right Bank Heated Oxygen Sensor (front) Circuit

4

POWERTRAIN CONTROL MODULE (PCM)

12

2

3

1

18

57

72

RIGHT BANK HEATED OXYGEN
SENSOR (FRONT)

TO PCM

FROM MFI RELAY

C-90

C-91

1 2
3 4

A-07
MU802605

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)

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

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-204

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 72) from the output terminal (terminal
No. 4) of the right bank heated oxygen sensor
(front).

• Terminal No. 2 of the right bank heated oxygen

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

.

TECHNICAL DESCRIPTION

• The right bank heated oxygen sensor (front)

detects the concentration of oxygen in the
exhaust gas; it converts those data to voltage,
and inputs the resulting signals to the PCM.

• When the right bank heated oxygen sensor

(front) begins to deteriorate, the heated oxygen
sensor signal response becomes poor.

• The PCM forcibly varies the air/fuel mixture to

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

.

DESCRIPTIONS OF MONITOR METHODS
Right bank heated oxygen sensor (front) rich/lean

switching frequency is under specified value.

.

MONITOR EXECUTION
Continuous

.

AK200489

A-07(B)

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

AB

CONNECTOR: A-07

AK103912AB

CONNECTOR: C-71

C-71

AK103738AE

CONNECTORS: C-90, C-91

PCM

C-91(GR)

C-90(GR)