Mitsubishi 380. Manual - part 416

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-204

STEP 8. Replace the valve body.
(1) Replace the valve body. Refer to GROUP 23B, 

Transmission 

23B-62

.

(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.

Q: Is A/T Item 10 set?

YES : Replace the torque converter. Refer to GROUP 23B, 

Transmission 

23B-13

.

NO :  The procedure is complete.

(P0742): Damper Clutch Control is Stuck On

.

DTC SET CONDITIONS

Check Conditions

• Throttle position sensor voltage: 1.5 volts or 

more.

• Output speed: 1,000 r/min or more.

• Solenoid status: OFF.

• Transmission inhibitor switch position: D, 3, 2 or 

L.

• Time after lock up clutch release: 5 seconds or 

more.

Judgement Criteria

• Calculated slip (engine speed - input speed): 5 

r/min or more. (5 seconds)

• Calculated slip (engine speed - input speed): -5 

r/min or less. (5 seconds)

.

OBD-II DRIVE CYCLE PATTERN

Start the engine, and drive at 30 km/h  for 30 sec-
onds. Then stop the vehicle, and turn "LOCK" (OFF) 
the ignition switch. After that, restart the engine, and 
drive again at 30 km/h (19 mph) for 30 seconds.

.

TROUBLESHOOTING HINTS (THE MOST 
LIKELY CAUSES FOR THIS CODE TO BE 
SET ARE:)

• Malfunction of the damper clutch control solenoid 

valve

• Malfunction of the valve body

• Damaged harness or connector

• Malfunction of the A/T-ECU

Circuit drawings

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• Refer to component locations GROUP-

70

DIAGNOSIS

Required Special Tool:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

VALVE BODY
ASSEMBLY

10DB117A

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-205

STEP 1. Using diagnostic tool MB991958, read the A/T 
diagnostic trouble code.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting diagnostic tool 
MB991958.
(1) Connect diagnostic tool MB991958 to the data link 

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Check for A/T diagnostic trouble code.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is (P0743) set?

YES : Refer to 

P.23A-185

, (P0743): Damper Clutch Control 

Solenoid Valve System.

NO :  Go to Step 2.

STEP 2. Using diagnostic tool MB991958, check A/T data 
list item 10: Amount of Damper Clutch Control Slippage.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting diagnostic tool 
MB991958.
(1) Connect diagnostic tool MB991958 to the data link 

connector.

(2) Start the engine. (Warming up engine)
(3) Set diagnostic tool MB991958 to the data reading mode.

• Item 10: Damper Clutch Control Amount of Slippage.

• Driving at a constant speed of 60 km/h, the display 

should be "

−10 to 10 r/min."

• If the accelerator pedal is released, the display on 

the diagnostic tool changes (50 km/h and less).

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

Q: Is the damper clutch control slippage within the 

specified range?
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

.

NO :  Go to Step 3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-206

STEP 3. Replace the A/T-ECU.
(1) Replace the A/T-ECU.
(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.

Q: Is (P0742) set?

YES : Go to Step 4.
NO :  The procedure is complete.

STEP 4. Replace the valve body.
(1) Replace the valve body. Refer to GROUP 23B, 

Transmission 

23B-62

.

(2) Test drive the vehicle.
(3) Check for A/T diagnostic trouble code.

Q: Is (P0742) set?

YES : Replace the Torque Converter. Refer to GROUP 23B, 

Transmission 

23B-13

.

NO :  The procedure is complete.

VALVE BODY
ASSEMBLY

10DB117A

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-207

(P1751): A/T Control Relay System

.

AC306223

A-13 (GR)

AB

CONNECTOR: A-13

1

4

7

8

2 3

5

13 14

17

15

12

16

11

10

9

6

10DB098A

RELAY BOX

CONNECTOR: B-16X

 

2

1

3 4

FRONT OF
VEHICLE

16DB564A

COVER

AIR

CLEANER

A/T

CONTROL

UNIT

CONNECTORS:  B-19, B-22

10DB084A

CONNECTORS: C-214, 215

1
3 4

2
6

5

C-214

C-215

6

1
7

2

9

8

10

3

5

12

11

4

1314