Mitsubishi Eclipse. Manual - part 200

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-293

STEP 13. Check the heated oxygen sensor (rear).
(1) Disconnect the heated oxygen sensor (rear) connector 

C-23 and connect test harness special tool, MB991658, to 
the connector on the 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 heated oxygen sensor 
(rear).

(3) Use the jumper wires to connect terminal No. 5 to the 

positive battery terminal and terminal No. 6 to the negative 
battery terminal.

(4) Connect a digital volt meter between terminal No. 3 and 

terminal No. 4.

(5) While repeatedly revving the engine, measure the 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 14.
NO :  Replace the heated oxygen sensor (rear). Then go to 

Step 14.

AK300412

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

C-54 (GR)

CONNECTOR: C-54 <A/T>

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AK300405

2

1

6 5 4 3

AB

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

HARNESS 
CONNECTOR:
HARNESS SIDE

AK000122

JUMPER
WIRES

MB991658

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-294

STEP 14. 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-5

.

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

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

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

AK103266

BL

ACK

BL

UE

YELL

OW

FROM MFI RELAY

HEATED OXYGEN
SENSOR (REAR)

     C-23
MU801448

TO ECM
OR PCM

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

75 <M/T>
73 <A/T>*2

92 <M/T>
57 <A/T>*1

C-60 <M/T>
(MU803772)

C-54 <A/T>
(MU803781)

C-57 <A/T>
(MU803782)

NOTE
*1:PCM connector C-54 <A/T>
*2:PCM connector C-57 <A/T>

5

6

4

3

1

2

3 4 5 6

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

82

78

81

80

89 90 91 92

79

87

71

74

73

72

76

75

77

85

88

83 84

86

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

Heated Oxygen Sensor (rear) Circuit

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-295

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 75) <M/T> or PCM (terminal No. 73) 
<A/T> from the output terminal (terminal No. 3) of 
the heated oxygen sensor (rear).

• Terminal No. 4 of the heated oxygen sensor 

(rear) is grounded with ECM (terminal No. 92) 
<M/T> or PCM (terminal No. 57) <A/T>.

.

TECHNICAL DESCRIPTION

• The output signal of the heated oxygen sensor 

(front) is compensated by the output signal of the 
heated oxygen sensor (rear).

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

open circuit in the heated oxygen sensor (rear) 
output line.

.

DESCRIPTIONS OF MONITOR METHODS
Heated oxygen sensor (rear) output voltage stays 

low when air/fuel ratio is forced to be rich. The 
above procedure is repeated when oxygen sen-
sor 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

.

AK300054AB

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

AK300060

ECM

CONNECTOR: C-60 <M/T>

AE

C-60 (G)

AK300060AB

C-54 (GR)

PCM

CONNECTOR: C-54 <A/T>

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-296

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• 3 minutes or more have passed since the starting 

sequence was completed.

• Heated oxygen sensor (rear) signal voltage has 

continued to be 0.15 volt or lower.

• Engine coolant temperature is higher than 76°C 

(169

°F).

• Engine speed is higher than 1,200 r/min.

• Volumetric efficiency is higher than 25 percent.

• Volume airflow sensor output frequency is 88 Hz 

or more.

START

V

F

 > =4.5V

2secs HAS PASSED

YES

YES

YES

NO

NO

NO

MALFUNCTION

MONITORING

CONDITIONS

YES

NO

MONITORING

CONDITIONS

+5V ON

AK301440

V

F

 < 0.15V

10secs HAS PASSED

YES

YES

NO

NO

END

MALFUNCTION

GOOD

MODULATE A/F CONDITION TO RICH