Mitsubishi 380. Manual - part 429

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-256

STEP 4. Using diagnostic tool MB991958, check data list 
item 27: Select Switch, item 28: Shift Switch (Up), item 29: 
Shift Switch (Down).

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) Set diagnostic tool MB991958 to the data reading mode for 

following items.

a. Item 27: Select Switch
b. Item 28: Shift Switch (Up)

c. Item 29: Shift Switch (Down)

NOTE: The switches above are displayed, depending on 
the selector lever condition as shown in the table.

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

Q: Is the switch 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 Malfunction 

P.00-14

.

NO :  Replace the A/T-ECU.

STEP 5. Check the shift switch assembly.
Refer to 

P.23A-303

, Transmission Control.

Q: Is the switch operating properly?

YES : Go to Step 6.
NO :  Replace the shift switch assembly. Refer to 

P.23A-302

, Transmission Control.

SELECTOR LEVER 
OPERATION

DATA LIST ITEM

27

28

29

D range

OFF

OFF

OFF

Sport mode

ON

OFF

OFF

Upshift and hold the selector 
lever

ON

ON

OFF

Downshift and hold the 
selector lever

ON

OFF

ON

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-257

STEP 6. Measure the power supply voltage at shift switch 
assembly connector D-14.
(1) Disconnect connector D-14 and measure at the harness 

side.

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

(3) Measure the voltage between terminal 2 and ground.

• The voltage should measure battery positive voltage.

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

Q: Is the measured voltage battery positive voltage?

YES : Go to Step 4.
NO :  Go to Step 7.

STEP 7. Check junction block connector C-214 and shift 
switch assembly connector D-14 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 8.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

.

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14

10DB126A

(D-14) FLOOR HARNESS 

CONNECTOR: 

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14

10DB085A

CONNECTOR: C-214

6

1
7

2

9

8

10

3

5

12

11

4

1314

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-258

STEP 8. Check the harness for open circuit or short circuit 
to ground between junction block connector C-214 
terminal 12 and shift switch assembly connector D-14 
terminal 2.
Q: Is the harness wire in good condition?

YES : Go to Step 4.
NO :  Repair or replace the harness wire.

STEP 9. Measure the power supply voltage at shift switch 
assembly connector D-14.
(1) Disconnect connector D-14 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.
(3) Move the selector lever to the "D" position.

(4) Measure the voltage between terminal 1 and ground.

• The voltage should measure battery positive voltage.

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

Q: Is the measured voltage battery positive voltage?

YES : Go to Step 12.
NO :  Go to Step 10.

10DB085A

CONNECTOR: C-214

6

1
7

2

9

8

10

3

5

12

11

4

1314

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14

10DB127A

(D-14) FLOOR HARNESS 

CONNECTOR: 

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-259

STEP 10. Check intermediate connector A-13 and shift 
switch assembly connector D-14 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 11.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

.

STEP 11. Check harness for open circuit or short circuit to 
ground between transmission inhibitor switch connector 
B-110 terminal 1 and shift switch assembly connector D-14 
terminal 1.
Q: Is the harness wire in good condition?

YES : Go to Step 4.
NO :  Repair or replace the harness wire.

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

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14

AC210068

CONNECTOR: B-110

B-110 (B)

AE

TRANSMISSION
RANGE SWITCH

1

7

2

8

3

5

9

4

10

6

10DB093A

CONNECTOR:  D-14

FLOOR

WIRING

HARNESS

4

Y

2

15

ROOF

WIRING

HARNESS

D-14