Mitsubishi Outlander GS45X. Manual - part 838

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-285

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 40) 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. 
41).

• The ECM applies an offset voltage of 0.5 volt to 

terminal No. 2 of the left bank heated oxygen 
sensor (rear).

.

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 check for the left bank heated oxygen 

sensor (rear) output voltage.

.

DESCRIPTIONS OF MONITOR METHODS

Left bank heated oxygen sensor (rear) out put volt-
age is under the 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)

• Heated oxygen sensor (front) monitor

• Heated oxygen sensor (rear) heater monitor

• Heated oxygen sensor (front) heater monitor

• Heated oxygen sensor (front) inactive monitor

• Heated oxygen sensor offset voltage monitor

• Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be 

normal)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-286

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Heated oxygen sensor offset voltage is between 

0.4 and 0.6 volt.

• Battery positive voltage is between 11 and 16.5 

volts.

• 3 minutes or more have passed since the engine 

starting sequence was completed.

Judgement Criterion

• Left bank heated oxygen sensor (rear) output 

voltage is lower than 0.2 volt for 2 seconds.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Pattern 21 

P.13B-11

.

.

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

• Left bank heated oxygen sensor (rear) failed.

• Connector damage.

• Harness damage.

• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991316: Test Harness

End

Malfunction

Yes

Yes

Yes

No

No

No

2secs have passed?

Output voltage

< 0.2V

Monitoring
conditions

Good

Start

AK700471

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-287

STEP 1. Check harness connector B-13 at the left bank 
heated oxygen sensor (rear) and harness connector B-10 
at the ECM 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 5.

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

connector B-13 and connect test harness special tool, 
MD991316 to the connector on the left bank heated oxygen 
sensor (rear) side.

(2) Warm up the engine until engine coolant temperature 

reaches 80

°C (176°F) or higher.

(3) Drive at 50 km/h (31 mph) or more for 10 minutes.
(4) Connect a digital voltage meter between terminal No. 2 

(black clip) and terminal No. 4 (white clip).

(5) Measure the output voltage of heated oxygen sensor under 

the following driving.

a. Transaxle: 2nd speed
b. Drive with wide open throttle

c. Engine: 3,500 r/min or more

Standard value: 0.6 

− 1.0 volts

NOTE: If the temperature of sensing area does not reach 
the high temperature [of approximately 400

°

C (752

°

F) or 

more] even though the oxygen sensor is normal, the output 
voltage would be possibly low in spite of the rich air-fuel 
ratio.
NOTE: When the vehicle is driven with high loads, the tem-
perature of the sensing area of the heated oxygen sensor is 
sufficiently high. Thus, it is not necessary to apply the volt-
age to the heater.

Q: Is the measured resistance between 11 and 18 ohms [at 

20

°C (68°F)?

YES : Go to Step 3.
NO :  Replace the left bank heated oxygen sensor (rear). 

Then go to Step 5.

AK700551

Heated
oxygen
sensor
component
side
connector

MB991316

Black

White

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-288

STEP 3. Check for harness between the left bank heated 
oxygen sensor (rear) connector B-13 and ECM connector 
B-10.
(1) Disconnect the left bank heated oxygen sensor (rear) 

connector B-13 and the ECM connector B-10.

(2) Measure the resistance between the heated oxygen sensor 

connector B-13 and the ECM connector B-10.

a. Connector B-13 (terminal No. 2) and connector B-10 

(terminal No. 41).

b. Connector B-13 (terminal No. 4) and connector B-10 

(terminal No. 40).

• Should be less than 2 ohms.

(3) Check for the continuity between the oxygen sensor 

connector B-13 and ground.

a. Connector B-13 (terminal No. 2) and ground
b. Connector B-13 (terminal No. 4) and ground

• Not continuity.

Q: Is the harness wire in good condition?

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

Inspection 

P.00E-2

. Then go to Step 5.

AK700289

1

2

3

4

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2

1

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64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

AB

B-13 harness
connector:
component side

B-10 harness
connector:
component side

1

2

3

4

AK700290AB

B-13 harness
connector:
component side