Mitsubishi Eclipse. Manual - part 201

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-297

• At least 20 seconds have passed since fuel shut 

off control was canceled.

• Monitoring time: 10 seconds.

Judgement Criteria

• Making the air/fuel ratio 15 percent for 10 sec-

onds richer does not result in raising the heated 
oxygen sensor (rear) output voltage beyond 0.15 
volt.

.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function 

− OBD-ll Drive Cycle − 

Procedure 6 

− Other Monitor 

P.13A-5

.

.

TROUBLESHOOTING HINTS (The most likely 
causes for this code to be set are: )

• Heated oxygen sensor (rear) failed.

• Short circuit in heated oxygen sensor (rear) out-

put line.

• Connector damage.

• ECM failed. <M/T>

• PCM failed. <A/T>

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

• MB991658: Test Harness 

STEP 1. Using scan tool MB991958, check data list item 59: 
Heated Oxygen Sensor (rear).

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item 

59, Heated Oxygen Sensor (rear).

• Warming up the engine. When the engine is revved, the 

output voltage should repeat 0 volt and 0.6 to 1.0 volt 
alternately.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent. 

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

P.00-6

.

NO :  Go to Step 2.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-298

STEP 2. 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 right bank 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 : Go to Step 3.
NO :  Replace the heated oxygen sensor (rear). Then go to 

Step 5.

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-299

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

YES : Go to Step 4.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 5.

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-300

STEP 4. Check for short circuit to ground between heated 
oxygen sensor (rear) connector C-23 (terminal No. 1) and 
ECM connector C-60 (terminal No. 75) <M/T> or PCM 
connector C-57 (terminal No. 73) <A/T>.
Q: Is the harness wire in good condition?

YES : Replace the ECM or PCM. Then go to Step 5.
NO :  Repair it. Then go to Step 5.

AK300735

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-57 <A/T>

C-57 (GR)

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