Mitsubishi Outlander GS45X. Manual - part 566

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-87

.

CIRCUIT OPERATION

• Power is supplied from the MFI relay (terminal 

No. 2) to the linear air-fuel ratio sensor heater.

• The ECM (terminal No. 34) controls continuity to 

the linear air-fuel ratio sensor heater by turning 
the power transistor in the ECM "ON" and "OFF".

.

TECHNICAL DESCRIPTION

• The ECM checks whether the heater current is 

within a specified range when the heater is ener-
gized.

• The ECM checks whether the heater voltage is 

within a specified range when the heater is not 
energized.

.

DESCRIPTIONS OF MONITOR METHODS

Linear air-fuel ratio sensor heater current or voltage 

is out of specified range.

.

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)

• Not applicable

.

AK704087AB

Connector: A-13

A-13

AK704088

MFI relay

AB

Connector: A-33X

A-33X

AK704090AB

Connector: B-10

B-10 (GR)

AK704089AD

Linear air-fuel
ratio sensor

SRS-ECU

Connector: C-142

C-142 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-88

DTC SET CONDITIONS
Logic Flow Chart

.

Check Conditions

• More than 2 seconds have passed since the 

engine starting sequence was completed.

• While the linear air-fuel ratio sensor heater is on.

• Battery positive voltage is between 11 and 16.5 

volts.

Judgement Criterion

• The linear air-fuel ratio sensor heater current has 

continued to be lower than average 0.17 ampere 
for 2 seconds.

Check Conditions

• More than 2 seconds have passed since the 

engine starting sequence was completed.

• While the linear air-fuel ratio sensor heater is off.

• Battery positive voltage is between 11 and 16.5 

volts.

Judgement Criterion

• The linear air-fuel ratio sensor heater voltage has 

continued to be lower than average 2.0 volts for 2 
seconds.

.

OBD-II DRIVE CYCLE PATTERN

• Refer to Diagnostic Function − OBD-II Drive 

Cycle 

− Pattern 2 

P.13A-11

.

.

End

No

No

Malfunction

Good

Current < 0.17A

or

Current > 10.5A

Voltage < 2.0V

AK900352

Heater activation 
command ON

No

No

Start

Yes

Yes

Yes

Yes

Yes

No

Continuous
failure for 2secs

Monitoring
conditions

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-89

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

• Open or shorted linear air-fuel ratio sensor heater 

circuit, harness damage or connector damage.

• Linear air-fuel ratio sensor heater failed.

• ECM failed. 

DIAGNOSIS

Required Special Tool:

• MB992110: Power Plant ECU Check Harness

STEP 1. Check harness connector C-142 at linear air-fuel 
ratio sensor for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 2.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 11.

STEP 2. Check the linear air-fuel ratio sensor.
(1) Disconnect the linear air-fuel ratio sensor connector C-142.
(2) Measure the resistance between linear air-fuel ratio sensor 

connector terminal No. 2 and terminal No. 3.

Standard value: 2.3 

− 4.2 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 2.3 and 4.2 ohms 

[at 20

°C (68°F)]?

YES : Go to Step 3.
NO :  Replace the linear air-fuel ratio sensor. Then go to 

Step 11.

STEP 3. Measure the power supply voltage at linear air-fuel 
ratio sensor harness side connector C-142.
(1) Disconnect the connector C-142 and measure at the 

harness side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 3 and ground.

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 5.
NO :  Go to Step 4.

AK900847

3

2

1

6

5

4

Linear air-fuel 
ratio sensor 
connector

AB

AK900652

1

2

3

4

5

6

C-142 harness
connector:
component side 

AE

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-90

STEP 4. Check harness connector A-33X at MFI relay for 
damage.
Q: Is the harness connector in good condition?

YES : Repair harness wire between MFI relay connector 

A-33X (terminal No. 2) and linear air-fuel ratio sensor 
connector C-142 (terminal No. 3) because of open 
circuit or short circuit to ground. Then go to Step 11.

NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 11.

STEP 5. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 6.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 11.