Mitsubishi Montero (2004+). Manual - part 215

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-347

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• 2 seconds or more have passed since the engine 

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: )

• Short circuit in left bank heated oxygen sensor 

(rear) output line.

• Connector damage.

• PCM failed.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

START

END

NO

NO

YES

YES

MALFUNCTION

GOOD

2secs HAVE PASSED?

OUTPUT VOLTAGE > 1.2V

NO

YES

MONITORING

CONDITIONS

AK302931

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-348

STEP 1. Check connector C-15 at left bank heated oxygen 
sensor (rear) and connector D-135 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.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AC

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT 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-349

STEP 2. Check for short circuit to power supply between 
left bank heated oxygen sensor (rear) connector C-15 
(terminal No. 4) and PCM connector D-135 (terminal No. 
116).

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

P.00E-2

. Then go to Step 3.

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.

AK201280

1

2

3

4

CONNECTOR: C-15

C-15(B)

AC

HARNESS 
CONNECTOR: 
COMPONENT SIDE

LEFT 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-350

STEP 3. Perform 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 P0158 set?

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

DTC P0159: Heated Oxygen Sensor Circuit Slow Response (bank 2, sensor 2)

WHITE

BL

ACK

BL

ACK

WHITE

BL

ACK

BL

ACK

BL

ACK

AK201137

TO PCM

FROM MFI RELAY

96

116

2

4

3

1

2

1

4 5 6

3

E-112

LEFT BANK
HEATED OXYGEN
SENSOR (REAR)

POWERTRAIN CONTROL
MODULE (PCM)

10

9

1

3

7

4

3

1 2

C-15

MU802605

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

Left Bank Heated Oxygen Sensor (rear) Circuit

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

D-135

(MU803805)