Mitsubishi Eclipse. Manual - part 472

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-431

STEP 3. Check harness connector B-23 at left bank heated 
oxygen sensor (rear) and harness connector C-58, C-62 at 
ECM or C-55, C-59 at PCM for damage.
Q: Is the harness connector in good condition?

YES : Replace the 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.

AK300410

1

2

3

4

LEFT BANK 
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-23

AB

B-23 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK300441

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

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

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

C-58 (GR)

C-62 (GR)

AB

C-62 HARNESS CONNECTOR:
COMPONENT SIDE

C-58 HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-432

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.13B-7

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0159 set?

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

AK300459

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-55, C-59 <A/T>

C-55 (GR)

C-59 (GR)

AB

C-59 HARNESS CONNECTOR:
COMPONENT SIDE

C-55 HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-433

DTC P0161: Heated Oxygen Sensor Heater Circuit (bank 2, sensor 2)

AK101603

RED

-

WHITE

RED

-

WHITE

RED

-

WHITE

RED

BL

UE-

WHITE

3 4

1 2

BATTERY

MFI
RELAY

LEFT BANK HEATED
OXYGEN SENSOR (REAR)

TO ECM
OR PCM

TO ECM
OR PCM

4

3

1

4

2

2

1

3

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

26

     B-23
MU802665

C-51 <M/T>, C-52 <A/T>
         (MU803784)

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

Left Bank Heated Oxygen Sensor (rear) Heater Circuit

3 4

1 2

A-18X

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-434

.

CIRCUIT OPERATION

• Power is supplied from the MFI relay (terminal 4) 

to the left bank heated oxygen sensor (rear) 
heater.

• The ECM (terminal No. 26) <M/T> or PCM (termi-

nal No. 26) <A/T> controls continuity to the left 
bank heated oxygen sensor (rear) heater by turn-
ing 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
Left bank 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

.

AK300058

LEFT BANK 
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-23

AB

B-23 (GR)

AK300121

MFI RELAY

CONNECTOR: A-18X

AB

A-18X

AK300091

CONNECTOR: C-51 <M/T>

ECM

AF

C-51 (GR)

AK300244

CONNECTOR: C-52 <A/T>

AC

PCM

C-52 (GR)