Mitsubishi 380. Manual - part 621

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-576

STEP 5. Using diagnostic tool, check actuator test items
01, 02, 03, 04, 05, 06: Injector.

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing or disconnecting diagnostic tool.
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check following items in the actuator test. Refer to Actuator

Test Reference Table

P.13A-644

a. Item 01, 02, 03, 04, 05, 06: Injector.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Are they operating properly?

YES : Go to Step 6.
NO : Refer to DTC P0201

− Injector Circuit.

STEP 6. Using diagnostic tool, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List

Reference Table

P.13A-637

a. Item 06: Engine Coolant Temperature Sensor.

(3) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-577

STEP 7. Check the fuel pressure.
Refer to On-vehicle Service

− Fuel Pressure Test

P.13A-661

Q: Is the fuel pressure normal?

YES : Go to Step 8.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 8. Check the advance ignition timing.
Ignition timing is controlled by the ENGIN-ECUand will vary
depending on engine requirement..

Q: Is the advance ignition timing normal?

YES : Check the following items, and repair or replace the

defective items.

a. Check the ignition coil and spark plugs.
b. Check compression pressure.

c. Check the engine oil viscosity.

Then confirm that the malfunction symptom is

eliminated.

NO : Check that the crankshaft position sensor and timing

belt cover are in the correct position. Then confirm
that the malfunction symptom is eliminated.

INSPECTION PROCEDURE 12: When the Engine Is Hot, It Stalls at Idle (Die Out).

COMMENT

• In cases such as the above, the ignition system,

air/fuel mixture, electronic control throttle valve
system or compression pressure may be faulty. In
addition, if the engine suddenly stalls, the cause
may also be a connector damage.

TROUBLESHOOTING HINTS (The most
likely causes for this case:)

• Malfunction of the ignition system.

• Malfunction of air/fuel ratio control system.

• Malfunction of the electronic control throttle valve

system.

• Vacuum leak.

• Improper connector contact.

• Refer to component locations GROUP-

• Refer to configuration diagrams GROUP-

• Refer to circuit diagrams GROUP-

DIAGNOSIS

Required Special Tools:

• Diagnostic tool(MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Check if the battery terminal is disconnected.

Q: Has the battery terminal been disconnected lately?

YES : Start the engine and let it run at idle for approximate

10 minutes after engine warm up. Then, if a
malfunction occurs, go to step 2.

NO : Go to Step 2.

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-578

STEP 2. Using diagnostic tool, read the diagnostic trouble
code (DTC).

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing or disconnecting diagnostic tool.
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13A-17

NO : Go to Step 3.

STEP 3. Using diagnostic tool, check actuator test items
01, 02, 03, 04, 05, 06: Injector.

CAUTION

Test Reference Table

P.13A-644

a. Item 01, 02, 03, 04, 05, 06: Injector.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Are they operating properly?

YES : Go to Step 4.
NO : Refer to DTC P0201

− Injector Circuit.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-579

STEP 4. Checking by depressing and releasing the
accelerator pedal.

Q: Does the engine stall right after the accelerator pedal is

released?
YES : Refer to On-vehicle Service

− Throttle Body (Throttle

Valve Area) Cleaning

P.13A-660

NO : Go to Step 5.

STEP 5. Engine stall reproduction test.

Q: Is it easy to reproduce the engine stall?

YES : Go to Step 6.
NO : Check if the following signals change suddenly by

wiggling the circuit harness and connectors.

a. Crankshaft position sensor signal.
b. Mass airflow sensor signal.

c. Injector drive signal.

d. Primary and secondary ignition signal.
e. Fuel pump drive signal.

f. ECU power supply voltage.

Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

STEP 6. Using diagnostic tool, check data list.

CAUTION

To prevent damage to diagnostic tool, always turn the igni-
tion switch to the "LOCK" (OFF) position before connect-
ing or disconnecting diagnostic tool.
(1) Connect diagnostic tool to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check the following items in the data list. Refer to Data List

Reference Table

P.13A-637

a. Item 05: Intake Air Temperature Sensor.
b. Item 06: Engine Coolant Temperature Sensor.

c. Item AD: Right Bank Heated Oxygen Sensor (rear).

d. Item AC: Right Bank Heated Oxygen Sensor (front).
e. Item AF: Left Bank Heated Oxygen Sensor (rear).

f. Item AE: Left Bank Heated Oxygen Sensor (front).

g. Item 83: Power Steering Pressure Switch.
h. Item 13: Throttle position sensor (main).

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Are they operating properly?

YES : Go to Step 7.
NO : Repair or replace it. Then confirm that the malfunction

symptom is eliminated.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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