Mitsubishi Eclipse. Manual - part 205

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-313

STEP 3. Check harness connector C-23 at heated oxygen 
sensor (rear) and harness connector C-60 at ECM <M/T> or 
C-54, C-57 at PCM <M/T> for damage.
Q: Is the harness connector in good condition?

YES : Replace the ECM or PCM.Then go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 4.

AK300405

2

1

6 5 4 3

AB

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

HARNESS 
CONNECTOR:
HARNESS SIDE

AK300415

82

78

8180

89

90

91

92

79

87

71

74 73 72

76 75

77

85

88

83

84

86

CONNECTOR: C-60 <M/T>

AB

C-60 (G)

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-314

STEP 4. 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 4 − 

Heated Oxygen Sensor Monitor 

P.13A-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0139 set?

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

AK300418

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

97

CONNECTORS: C-54, C-57 <A/T>

C-57 (GR)

C-54 (GR)

AB

C-57 HARNESS CONNECTOR:
COMPONENT SIDE

C-54 HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-315

DTC P0141: Heated Oxygen Sensor Heater Circuit (sensor 2)

AK101514

5 6

3 4

2

1

RED

-

WHITE

RED

-

WHITE

RED

-

WHITE

RED

BL

UE-

WHITE

BATTERY

MFI
RELAY

HEATED OXYGEN
SENSOR (REAR)

    C-23
MU801448

TO ECM
OR PCM

TO ECM
OR PCM

4

3

Heated Oxygen Sensor (rear) Heater Circuit

1

3

2

4

5

6

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

54 <M/T>
26 <A/T>

C-50 <A/T>
(MU803784)

C-56 <M/T>
(MU803770)

57 58

60 61

53

52

51

55

54

56

59

62

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

21 22 23

24 25

26 27 28 29

3132 33

34 35

1

10

3 4

1 2

A-18X

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-316

.

CIRCUIT OPERATION

• Power is supplied from the MFI relay (terminal 

No. 4) to the heated oxygen sensor (rear) heater.

• The ECM (terminal No. 54) <M/T> or PCM (termi-

nal No. 26) <A/T> controls continuity to the 
heated oxygen sensor (rear) heater by turning 
the power transistor in the ECM <M/T> or PCM 
<A/T> "ON" and "OFF".

.

BACKGROUND

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

the heater current is within a specified range 
when the heater is energized.

.

DESCRIPTIONS OF MONITOR METHODS
Heated oxygen sensor heater (rear) current is out of 

specified range when engine coolant temperature 
is over 20

°C (68°F).

.

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)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Engine coolant temperature sensor

.

AK300060

ECM

CONNECTOR: C-56 <M/T>

AF

C-56 (G)

AK300060AD

C-50 (GR)

PCM

CONNECTOR: C-50 <A/T>

AK300054AB

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

AK300121

MFI RELAY

CONNECTOR: A-18X

AB

A-18X