Mitsubishi Montero (2004+). Manual — part 189

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-243

STEP 3. Check connector C-14 at right bank heated
oxygen sensor (rear) and connector D-135 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.

AK201276

1

2

3

4

CONNECTOR: C-14

C-14(GR)

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR:
COMPONENT SIDE

AB

PCM

D-135(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-244

STEP 4. Check for short circuit to ground between right
bank heated oxygen sensor (rear) connector C-14
(terminal No. 4) and PCM connector D-135 (terminal No.
117).

NOTE: Check harness after checking intermediate connector,
E-112. If intermediate connector is damaged, repair or replace
it. Refer to GROUP 00E, Harness Connector Inspection

P.00E-2

.

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.

AK201276

1

2

3

4

CONNECTOR: C-14

C-14(GR)

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK200947

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR:
COMPONENT SIDE

AB

PCM

D-135(GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-245

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 P0137 set?

YES : Retry the troubleshooting.
NO : The inspection is complete.

DTC P0138: Heated Oxygen Sensor Circuit High Voltage (bank 1, sensor 2)

WHITE

BL

ACK

BL

ACK

WHITE

BL

ACK

BL

ACK

BL

ACK

2

1

4 5 6

3

AK201133

TO PCM

FROM MFI RELAY

96

117

2

4

3

1

1

12

23 24 25 26

2

13

3

14

4

15

5

16

6

17

7

18

8

19

9

20 21 22

27 28 29 30 31 32 33

10 11

D-116

1
5

7 8

3 4
9 10

2
6

D-14

MU801335

E-112

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

POWERTRAIN CONTROL
MODULE (PCM)

9

9

5

4

7

4

3

1 2

C-14

MU802665

Right Bank Heated Oxygen Sensor (rear) Circuit

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

D-135

(MU803805)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-246

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the PCM (ter-
minal No. 117) 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.
96).

.

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.

.

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

• 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

.

AK201275

CONNECTOR: C-14

C-14(GR)

AB

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

AK201038AF

CONNECTOR: D-135

PCM

D-135(GR)

AK201049

D-14

AB

CONNECTOR: D-14

AK201049

CONNECTOR: D-116

D-116

AC

AK201052

E-112

AB

CONNECTOR: E-112