Mitsubishi 380. Manual - part 635

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-632

STEP 7. Check for open circuit, short circuit to ground or 
harness damage between ignition coil connector and ECU 
connector.

AK303233

1

2

3

AB

B-118 (GR)

B-102 (GR)

B-101 (GR)

B-117 (GR)

B-103 (GR)

B-114 (GR)

CONNECTOR: B-101, B-102, B-103, B-114,

                         B-117, B-118

HARNESS CONNECTOR:

COMPONENT SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-633

NOTE: Check harness after checking intermediate connector 
B-32. If intermediate connector is damaged, repair or replace it. 
Refer to GROUP 00E, Harness Connector Inspection. Then 
confirm that the malfunction symptom is eliminated.

a. Check the harness wire between ignition coil connector 

B-101 (terminal No. 3) and ECU connector B-20 (terminal 
No. 07) at ignition coil 1.

b. Check the harness wire between ignition coil connector 

B-118 (terminal No. 3) and ECU connector B-20 (terminal 
No. 22) at ignition coil 2.

c. Check the harness wire between ignition coil connector 

B-102 (terminal No. 3) and ECU connector B-20 (terminal 
No. 36) at ignition coil 3.

d. Check the harness wire between ignition coil connector 

B-117 (terminal No. 3) and ECU connector B-20 (terminal 
No. 51) at ignition coil 4.

e. Check the harness wire between ignition coil connector 

B-103 (terminal No. 3) and ECU connector B-20 (terminal 
No. 37) at ignition coil 5.

f. Check the harness wire between ignition coil connector 

B-114 (terminal No. 3) and ECU connector B-20 (terminal 
No. 52) at ignition coil 6.

Q: Is the harness wire in good condition?

YES : Replace the ECU. Then confirm that the malfunction 

symptom is eliminated.

NO :  Repair it. Then confirm that the malfunction symptom 

is eliminated.

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-634

INSPECTION PROCEDURE 28: A/C system.  

.

COMMENT

• When the A/C is "ON" the ECU turns "ON" the 

power transistor in the ECU. The ECU delays A/C 
engagement momentarily while it increases idle 
r/min. Then the A/C compressor clutch relay coil 
will be energized. 
With this, the A/C compressor clutch relay turns 
"ON", and the A/C compressor clutch operates.

.

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

• Malfunction of the A/C control system.

• Improper connector contact, open circuit or 

short-circuited harness wire.

• Malfunction of the ECU. 

• Refer to component locations GROUP-

70

• Refer to configuration diagrams GROUP-

80

• Refer to circuit diagrams GROUP-

90

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

MULTIPORT FUEL INJECTION (MPI) DIAGNOSIS

MULTIPORT FUEL INJECTION (MPI) <3.8L ENGINE>

13A-635

DIAGNOSIS

STEP 1. Using diagnostic tool, check actuator test item 16: 
A/C Relay.

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) Set diagnostic tool to the actuator test mode for item 16, 

A/C Relay.

• An operation sound of the relay should be heard.

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

Q: Is the A/C Relay operating properly?

YES : Replace the ECU. Then confirm that the malfunction 

sympton is eliminated.

NO :  Go to Step 2.

STEP 2. Check harness connector B-21 at ECU 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 confirm that the 

malfunction symptom is eliminated.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER