Mitsubishi Eclipse. Manual — part 190

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-253

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 P0133 set?

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

DTC P0134: Heated Oxygen Sensor Circuit No Activity Detected (sensor 1)

.

Heated Oxygen Sensor Circuit No Activity
Detected (sensor 1) Circuit

• Refer to, DTC P0130 Heated Oxygen Sensor

(front) Circuit

P.13A-214

.

• Refer to, DTC P0201, P0202, P0203, P0204 −

Injector Circuit

P.13A-377

.

.

CIRCUIT OPERATION

• Refer to, DTC P0130 Heated Oxygen Sensor

(front) Circuit

P.13A-214

.

• Refer to, DTC P0201, P0202, P0203, P0204 −

Injector Circuit

P.13A-377

.

.

TECHNICAL DESCRIPTION

• The ECM <M/T> or PCM <A/T> effects air/fuel

ratio feedback control in accordance with the sig-
nals from the heater oxygen sensor (front).

• If the heated oxygen sensor (front) has deterio-

rated, corrections will be made by the heated
oxygen sensor (rear).

• DTC P0134 is stored when abnormality of the

air/fuel ratio feedback control is detected.

.

DESCRIPTIONS OF MONITOR METHODS
Heated oxygen sensor (front) output voltage does

not cross 0.5 volt within specified period.

.

MONITOR EXECUTION
Continuous

.

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

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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-254

MONITOR EXECUTION CONDITIONS (Other
monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Misfire monitor

Sensor (The sensor below is determined to be

normal)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• 20 seconds or more have passed since the start-

ing sequence was completed.

• Engine coolant temperature is higher than 76°C

(169

°F).

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

• Volumetric efficiency is at between 30 and 80

percent.

• Throttle position sensor output voltage is lower

than 4.3 volts.

• Except while fuel is being shut off.

• Monitoring time: 30 seconds.

Judgment Criteria

• Heated oxygen sensor (front) output voltage does

not get across 0.5 volt within about 30 seconds.

.

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 (front) deteriorated.

• Harness damage in heated oxygen sensor (front)

output line.

• Heated oxygen sensor (rear) deteriorated.

HEATED OXYGEN SENSOR (FRONT)

OUTPUT VOLTAGE CROSSES 0.5V?

START

END

NO

NO

NO

YES

Yes

YES

MALFUNCTION

GOOD

30secs HAVE PASSED?

MONITORING

CONDITIONS

AK203999

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

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NOTE: When the heated oxygen sensor (front)
begins to deteriorate, the heated oxygen sensor
output voltage will deviate from the voltage when
the sensor was new (normally 0.5 volt at
stoichiometric ratio). This deviation will be cor-
rected by the heated oxygen sensor (rear).
If the heated oxygen sensor (rear) responds
poorly because it has deteriorated, it will improp-
erly correct the heated oxygen sensor (front).
Thus, even when closed loop control is being
effected, the fluctuation of the heated oxygen
sensor (front) output voltage decreases, without
intersecting with 0.5 volt. As a result, there is a
possibility of DTC P0134 becoming registered.

• Connector damage.

• Harness damage in injector circuit.

• Injector failed.

• ECM failed. <M/T>

• PCM failed. <A/T>

• Exhaust leak.

• Incurrect fuel pressure.

• Intake system vacuum leak.

DIAGNOSIS

Required Special Tools:

• MB991958 (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991911: Main Harness B

• MD998464: 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 : Go to Step 2.
NO : Refer to, DTC P0137

− Heated Oxygen Sensor Circuit

Low Voltage (sensor 2)

P.13A-294

, DTC P0138

−

Heated Oxygen Sensor Circuit High Voltage (sensor
2)

P.13A-302

, DTC P0139

− Heated Oxygen Sensor

Circuit Slow Response (sensor 2)

P.13A-308

.

STEP 2. Check the exhaust leaks.
Q: Are there any abnormalities?

YES : Go to Step 3.
NO : Repair it. Then go to Step 12.

AK300810

AB

MB991911

16-PIN

MB991827

MB991824

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L>

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STEP 3. Check the intake system vacuum leak.
Q: Are there any abnormalities?

YES : Go to Step 4.
NO : Repair it. Then go to Step 12.

STEP 4. Check connector B-17 at the heated oxygen
sensor (front) for damage.
Q: Is the connector in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 12.

AK300403

1

2

3

4

AB

B-17 (B)

HEATED OXYGEN
SENSOR (FRONT)

CONNECTOR: B-17

HARNESS
CONNECTOR:
COMPONENT SIDE