Mitsubishi 380. Manual - part 339

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-24

STEP 4. Check Engine ECU connector B-21 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Are the connector and terminals in good condition?

YES : Go to Step 5.
NO :  Repair the faulty connector if possible or as 

recommended, replace complete wiring  harness. 
(Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

). Install the air bag module (driver’s side). 

(Refer to GROUP 52B, Air Bag Modules and Clock 
Spring 

P.52B-237

). Then go to Step 18.

STEP 5. Check the harness for short circuit to ground 
between the Engine ECU connector B-21 terminal 14 and 
the auto-cruise control switch connector C-302 terminal 2.
(1) Disconnect Engine ECU connector B-21 and measure at 

the harness connector side.

(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Measure the continuity between Engine ECU connector 

B-21 terminal 14 and ground.

(4) Reconnect Engine ECU connector B-21.

Q: Is the measured continuity open circuit?

YES : Install the air bag module (driver’s side). (Refer to 

GROUP 52B, Air Bag Modules and Clock Spring 

P.52B-237

). Then go to Step 17.

NO :  Go to Step 6.

10DB133A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

10DB133A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-25

STEP 6. Check intermediate connector C-29, auto-cruise 
control switch connector C-302 and clock spring 
connectors C-303 and C-306 for loose, corroded or 
damaged terminals, or terminals pushed back in the 
connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 7.
NO :  Repair the faulty connector if possible or as 

recommended, replace complete wiring harness. 
(Refer to GROUP 00E, Harness Connector Inspection 

P.00E-2

). Install the air bag module (driver’s side). 

(Refer to GROUP 52B, Air Bag Modules and Clock 
Spring 

P.52B-237

). Then go to Step 18.

17DB041A

C-29

CONNECTOR: C-29

C-29 MALE SIDE CONNECTOR

17DB040A

C-306 HARNESS

CONNECTOR:

COMPONENT SIDE

C-303 HARNESS

CONNECTOR:

COMPONENT SIDE

C-302 HARNESS

CONNECTOR:

COMPONENT SIDE

C-302 (Y)

C-303 (GR)

C-306

CONNECTORS: C-302, C-303, C-306

CLOCK

SPRING

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-26

STEP 7. Check the harness wire between Engine ECU 
connector B-21 terminal 14 and auto-cruise control switch 
connector C-302 terminal 2 for damage.
Q: Are the harness wires in good condition?

YES : Go to Step 8.
NO :  Repair the damaged harness wire if possible or as 

recommended replace complete wiring harness and 
install the air bag module (driver’s side). (Refer to 
GROUP 52B, Air Bag Modules and Clock Spring 

P.52B-237

). Then go to Step 18.

STEP 8. Check the clock spring.
Refer to GROUP 52B, Air Bag Modules and Clock Spring 

P.52B-244

.

Q: Is the clock spring in good condition?

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 Malfunction 

P.00-14

). Install 

the air bag module (driver’s side). (Refer to GROUP 
52B, Air Bag Modules and Clock Spring 

P.52B-237

). 

Then go to Step 18.

NO :  Replace the clock spring and install the air bag 

module (driver’s side). (Refer to GROUP 52B, Air Bag 
Modules and Clock Spring 

P.52B-237

). Then go to 

Step 18.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

17DB042A

C-302 (Y)

CONNECTOR: C-302

C-302 HARNESS

CONNECTOR:

COMPONENT SIDE

CLOCK

SPRING

AUTO-CRUISE CONTROL

ENGINE AND EMISSION CONTROL

17-27

STEP 9. Measure the ground voltage at auto-cruise control 
switch connector C-302 by backprobing.
(1) Do not disconnect auto-cruise control switch connector 

C-302.

(2) Turn the ignition switch to the "ON" position.
(3) Turn the "CRUISE" (MAIN) switch to the "ON" position.

(4) Measure the ground voltage between auto-cruise control 

switch connector C-302 terminal 3 and ground by 
backprobing.

(5) Turn the "CRUISE" (MAIN) switch to the "OFF" position.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the measured voltage 0.5 volt or less?

YES : Go to Step 15.
NO :  Go to Step 10.

STEP 10. Measure the ground voltage at Engine ECU 
connector B-21.
(1) Disconnect all the connectors from the Engine ECU.
(2) Connect special tool MB992044 between the Engine ECU 

and the body-side harness connector.

(3) Turn the ignition switch to the "ON" position.
(4) Turn the "CRUISE" (MAIN) switch to the "ON" position.
(5) Measure the ground voltage between special tool 94-pin 

connector  terminal 15 (Engine ECU connector B-21 
terminal 15) and ground.

(6) Turn the "CRUISE" (MAIN) switch to the "OFF" position.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
(8) Disconnect special tool MB992044 between the Engine 

ECU and the body-side harness connector.

(9) Reconnect all the connectors to the Engine ECU.

Q: Is the measured voltage 0.5 volt or less?

YES : Go to Step 12.
NO :  Go to Step 11.

17DB042A

C-302 (Y)

CONNECTOR: C-302

C-302 HARNESS

CONNECTOR:

COMPONENT SIDE

CLOCK

SPRING

1 2

AC209264

3

AB

C-302 HARNESS

CONNECTOR:

HARNESS SIDE

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER