Mitsubishi Eclipse. Manual - part 438

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-295

AK300460

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

CONNECTOR: C-59 <A/T>

C-59 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300445

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97 96

100

89

78

71

90

76

77

75

72
79

CONNECTOR: C-62 <M/T>

C-62 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-296

STEP 14. Check the right bank heated oxygen sensor 
(rear).
(1) Disconnect the right bank heated oxygen sensor (rear) 

connector B-28 and connect test harness special tool, 
MB991316, to the connector on the right bank heated 
oxygen sensor (front) side.

(2) Warm up the engine until engine coolant 80

°C (176°F) or 

higher.

CAUTION

Be very careful when connecting the jumper wires; incor-
rect connection can damage the right bank heated oxygen 
sensor (rear).

(3) Use the jumper wires to connect terminal 1 (red clip) to the 

positive battery terminal and terminal 3 (blue clip) to the 
negative battery terminal.

(4) Connect a digital volt meter between terminal 2 (black clip) 

and terminal No. 4 (white clip).

(5) While repeatedly revving the engine, measure the right 

bank heated oxygen sensor (rear) output voltage.

Standard value: 0.6 

− 1.0 volt

Q: Is the voltage between 0.6 and 1.0 volt?

YES : Replace the ECM or PCM. Then go to Step 15.
NO :  Replace the right bank heated oxygen sensor (rear). 

Then go to Step 15.

STEP 15. 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.13B-7

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0136 set?

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

AK300429

1

2

3

4

RIGHT BANK 
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-28

AB

B-28 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AKX01625 AB

BLUE

JUMPER
WIRES

BLACK

RED

WHITE

MB991316

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-297

DTC P0137: Heated Oxygen Sensor Circuit Low Voltage (bank 1, sensor 2)

AK103015

BLA

CK

BLA

CK

PINK

BLUE

3 4

1 2

FROM MFI RELAY

RIGHT BANK HEATED
OXYGEN SENSOR (REAR)

TO ECM
OR PCM

74<M/T>*2
74<A/T>*4

49<M/T>*1
57<A/T>*3

1

3

2

4

     B-28
MU802665

NOTE
*1: ECM connector C-58 <M/T>
*2: ECM connector C-62 <M/T>
*3: PCM connector C-55 <A/T>
*4: PCM connector C-59 <A/T>

ENGINE CONTROL
MODULE (ECM) <M/T>
OR
POWERTRAIN CONTROL
MODULE (PCM) <A/T>

65

43
50

42
49

41
48
60 61

64

46 47
58 59
67 68

45

56
66

52

51

44

53

62

54

63

57

55

C-58 <M/T>
(MU803782)

C-55 <A/T>
(MU803781)

42 43
48 49 50 51 52 53 54 55 56 57

46

45

44

58 59

60 61 62 63

64 65 66

47

41

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

80

87

81

94

85

82

84

93

86

98

99

74

92

73

83

88

91

95

97

96

100

89

78

71

90

76 77

75

72
79

97

C-62 <M/T>
(MU803783)

C-59 <A/T>
(MU803782)

Right Bank Heated Oxygen Sensor (rear) Circuit

S142

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-298

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 74) <M/T> or PCM (terminal No. 74) 
<A/T> 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 ECM (terminal No. 
49) <M/T> or PCM (terminal No. 57) <A/T>.

.

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 ECM <M/T> or PCM <A/T> checks for an 

open circuit in the right bank heated oxygen sen-
sor (rear) output line.

.

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

age stays low when air/fuel ratio is forced to be 
rich. The above procedure is repeated when oxy-
gen sensor is inactive.

.

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

.

AK300075

RIGHT BANK 
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-28

AB

B-28 (GR)

AK300091

CONNECTORS: C-58, C-62 <M/T>

ECM

AD

C-58 (GR)

C-62 (GR)

AK300244

CONNECTORS: C-55, C-59 <A/T>

AD

PCM

C-55 (GR)

C-59 (GR)