Mitsubishi Outlander GS45X. Manual - part 800

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-133

.

CIRCUIT OPERATION

• The mass airflow sensor power is supplied from 

the MFI relay (terminal No. 2), and the ground is 
provided on the ECM (terminal No. 88).

• A voltage that is according to the mass airflow 

rate is sent to the ECM (terminal No. 87) from the 
mass airflow sensor output terminal (terminal No. 
3).

.

TECHNICAL DESCRIPTION

• While the engine is running, the mass airflow 

sensor outputs voltage which corresponds to the 
mass airflow rate.

• The ECM checks whether the voltage output by 

the mass airflow sensor while the engine is run-
ning is within a specified range.

.

DESCRIPTIONS OF MONITOR METHODS

Compare load value with mass airflow sensor output 

voltage.

.

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)

• Throttle position sensor

.

AK700406

AB

Mass airflow
sensor

A-07 (GR)

Connector: A-07

AK700402AB

ECM

B-11 (GR)

Connector: B-11

AK700399AB

MFI relay

A-33X

Connector: A-33X

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-134

DTC SET CONDITIONS <Range/Performance problem - low input>

Logic Flow Chart

.

Check Conditions

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

• Throttle position sensor output voltage is 1.5 volts 

or higher.

• Mass airflow sensor output voltage is 0.2 volt or 

higher.

Judgement Criterion

• Mass airflow sensor output voltage has continued 

to be 1.8 volts or lower for 2 seconds.

.

Start

End

No

Yes

Yes

Yes

No

No

Malfunction

Good

Continuous

failure for 2secs

Output voltage

< = 1.8V

Monitoring
conditions

AK700457

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-135

DTC SET CONDITIONS <Range/Performance problem - high input>

Logic Flow Chart

.

Check Conditions

• Throttle position sensor output voltage is 0.8 volt 

or lower.

• Mass airflow sensor output voltage is 4.9 volts or 

lower.

Judgement Criterion

• Mass airflow sensor output voltage has continued 

to be 2.5 volts or higher for 2 seconds.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function 

− OBD-II Drive Cycle − 

Pattern 7 

P.13B-11

.

.

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

• Mass airflow sensor failed.

• Connector damage

• Harness damage

• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

End

No

No

No

Malfunction

Good

Output voltage

>= 2.5 V

AK900353

Start

Yes

Yes

Yes

Continuous
failure for 2secs

Monitoring
conditions

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-136

STEP 1. Using scan tool MB991958, check data list item 10: 
Mass Airflow Sensor.

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 

10, Mass Airflow Sensor.

(4) Warm up the engine to normal operating temperature: 80

°C 

to 95

°C (176°F to 203°F).

• The standard value during idling should be between 

1,350 and 1,670 millivolts.

• When the engine is revved, the mass airflow rate should 

increase according to the increase in engine speed.

(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 

− How to 

Cope with Intermittent Malfunctions 

P.00-15

.

NO :  Go to Step 2.

STEP 2. Check harness connector A-07 at the mass airflow 
sensor and harness connector B-11 at the ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 3.
NO :  Repair it. Refer to GROUP 00E, Harness Connector 

Inspection 

P.00E-2

. Then go to Step 6.

AK700568AB

MB991824

MB991827

MB991910

Data link
connector