Mitsubishi 380. Manual - part 499

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-88

DIAGNOSIS

Required Special Tool:

• : Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Using diagnostic tool , check data list item AA: 
Mass Airflow Sensor.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool  to the data link connector.
(2) Start the engine and run at idle.
(3) Set diagnostic tool  to the data reading mode for item AA, 

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 approxi-

mately 4.7 g/sec.

• 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.00-14

.

NO :  Go to Step 2.

STEP 2. Check harness connector B-10 at mass airflow 
sensor for damage.
Q: Is the harness connector in good condition?

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

Connector Inspection 

P.00E-2

. Then go to Step 7.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

CONNECTOR: B-10

B-10 (GR)

03DB218A

HARNESS

CONNECTOR:

COMPONENT SIDE

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-89

STEP 3. Check the continuity at mass airflow sensor 
harness side connector B-10.
(1) Disconnect the connector B-10 and measure at the harness 

side.

(2) Check for the continuity between terminal No. 3 and 

ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 6.
NO :  Go to Step 4.

STEP 4. Check harness connector B-20 at ENGINE-ECU for 
damage.
Q: Is the harness 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 7.

CONNECTOR: B-10

B-10 (GR)

03DB218A

HARNESS

CONNECTOR:

COMPONENT SIDE

03DB219A

B-10 HARNESS 

CONNECTOR: 

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-90

STEP 5. Check for short circuit between mass airflow 
sensor connector B-10 (terminal No. 3) and ENGINE-ECU 
connector B-20 (terminal No. 26).
Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO :  Repair it. Then go to Step 7.

CONNECTOR: B-10

B-10 (GR)

03DB218A

HARNESS

CONNECTOR:

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPOINT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPOINT FUEL INJECTION (MPI)

13A-91

STEP 6. Using diagnostic tool , check data list item AA: 
Mass Airflow Sensor.

CAUTION

To prevent damage to diagnostic tool , always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting diagnostic tool .
(1) Connect diagnostic tool  to the data link connector.
(2) Start the engine and run at idle.
(3) Set diagnostic tool  to the data reading mode for item AA, 

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 approxi-

mately 4.7 g/sec.

• 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.00-14

.

NO :  Replace the Mass Airflow Sensor. Then go to Step 7.

STEP 7. Test the EOBD drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− EOBD Drive Cycle − 

P.13A-11

.

(2) Check the diagnostic trouble code (DTC).

Q: Is DTC P0103 set?

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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827