Mitsubishi Eclipse. Manual - part 204

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-309

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 75) <M/T> or PCM (terminal No. 73)
<A/T> from the output terminal (terminal No. 3) of
the heated oxygen sensor (rear).

• Terminal No. 4 of the heated oxygen sensor

(rear) is grounded with ECM (terminal No. 92)
<M/T> or PCM (terminal No. 57) <A/T>.

TECHNICAL DESCRIPTION

• The output signal of the heated oxygen sensor

(front) is compensated by the output signal of the
heated oxygen sensor (rear).

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

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

DESCRIPTIONS OF MONITOR METHODS
Heated oxygen sensor (rear) output voltage does not

change during specified go/stop operations
including fuel cut are repeated.

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

AK300054AB

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

AK300060

ECM

CONNECTOR: C-60 <M/T>

C-60 (G)

AK300060

PCM

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

C-57 (GR)

C-54 (GR)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-310

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• Engine coolant temperature is higher than 76°C

(169

°F).

• The heated oxygen sensor (front) is active.

• The cumulative volume airflow sensor output fre-

quency is higher than 4,000 Hz.

• Repeat 3 or more times: drive

, stop

Drive

• Engine speed is higher than 1,500 r/min.

• Volumetric efficiency is higher than 40 per-

cent.

• Vehicle speed is higher than 30 km/h (19

mph).

• A total of more than 10 seconds have

elapsed with the above mentioned condi-
tions, and more than 2 seconds have
elapsed with the fuel shut off.

Stop

• Vehicle speed is lower than 1.5 km/h (1

mph).

Judgement Criteria

• Change in the output voltage of the heated oxy-

gen sensor (rear) is lower than 0.313 volt.
NOTE: Monitoring stops after fuel has been shut
off for more than 38 seconds.

OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-ll Drive Cycle −

Procedure 4

− Heated Oxygen Sensor Monitor

P.13A-5

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

• Heated oxygen sensor (rear) failed.

• ECM failed. <M/T>

• PCM failed. <A/T>

END

YES

START

MONITORING

CONDITION

YES

MALFUNCTION

GOOD

F1: COUNTER OF A DRIVING STATE.
F2: COUNTER OF A STOP STATE.

OUTPUT VOLTAGE

CHANGE < 0.313 V

GO/STOP OPERATION

FOR SPECIFIED TIMES

YES

AK301442

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-311

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

69, Heated Oxygen Sensor (rear).

(4) Warm up the engine.

• After increasing the output voltage 0.15 volt or more by

the engine revving, finish it. Then confirm that the output
voltage reduces to 0.15 volt or less within 3 seconds.

(5) 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 : Replace the heated oxygen sensor (rear). Then go to

Step 2.

AK300810

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 2. Check the heated oxygen sensor (rear).
(1) Disconnect the right bank 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 heated oxygen sensor
(rear).

(3) Use the jumper wires to connect terminal No. 5 of the

heated oxygen sensor connect to the positive battery
terminal.

(4) Connect a digital voltage 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 4.

AK300405

6 5 4 3

C-23

HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: C-23

HARNESS
CONNECTOR:
HARNESS SIDE

AK000122

JUMPER
WIRES

MB991658

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