Mitsubishi Eclipse. Manual - part 462

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-391

STEP 10. Check for harness damage between left bank 
heated oxygen sensor (front) connector B-24 (terminal No. 
3) and ECM connector C-51 (terminal No. 3) <M/T> or PCM 
connector C-52 (terminal No. 3) <A/T>.
Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO :  Repair it. Then go to Step 12.

AK300424

1

2

3

4

LEFT BANK 
HEATED OXYGEN
SENSOR (FRONT)

CONNECTOR: B-24

AB

B-24 (B)

HARNESS CONNECTOR:
COMPONENT SIDE

AK300458

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

31

32

33

34

35

1

10

CONNECTOR: C-52 <A/T>

C-52 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-392

STEP 11. Check the trouble symptoms.
(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 P0155 set?

YES : Replace the ECM or PCM. Then go to Step 12.
NO :  It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use Troubleshooting/ 
Inspection Service Points 

P.00-6

.

STEP 12. 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 P0155 set?

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

AK300443

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

31

32

33

34

35

1

10

CONNECTOR: C-51 <M/T>

C-51 (GR)

AB

HARNESS CONNECTOR:
COMPONENT SIDE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-393

DTC P0156: Heated Oxygen Sensor Circuit (bank 2, sensor 2)

AK103016

BLA

C

K

BLUE

YELLO

W

3 4

1 2

FROM MFI RELAY

LEFT BANK HEATED
OXYGEN SENSOR (REAR)

TO ECM
OR PCM

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

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

1

3

2

4

     B-23
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)

Left Bank Heated Oxygen Sensor (rear) Circuit

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-394

.

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 73) <M/T> or PCM (terminal No. 73) 
<A/T> from the output terminal (terminal No. 4) of 
the left bank heated oxygen sensor (rear).

• Terminal No. 2 of the left 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 left bank heated oxygen 

sensor (front) is compensated by the output sig-
nal of the left bank heated oxygen sensor (rear).

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

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

.

DESCRIPTIONS OF MONITOR METHODS
Left bank heated oxygen sensor (rear) circuit is 

switched to 5 volts intentionally when oxygen 
sensor output is low, and detects the malfunction 
if the output voltage changes to equal or greater 
than 4.5 volts. The above procedure is repeated 
when oxygen 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

.

AK300058

LEFT BANK 
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-23

AB

B-23 (GR)

AK300244

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

AD

PCM

C-55 (GR)

C-59 (GR)

AK300091

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

ECM

AD

C-58 (GR)

C-62 (GR)