Mitsubishi Pajero Pinin. Manual - part 190

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-10

INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS

INSPECTION PROCEDURE 1

Communication with the MUT-

II

 is not possible

Probable cause

If communication with the MUT-

II

 is not possible, the cause is probably a malfunction

in the self-diagnosis system or the A/T-ECU is not functioning.



Malfunction of self-diagnosis system



Malfunction of A/T-ECU power circuit



Malfunction of A/T-ECU earth circuit



Malfunction of A/T-ECU



Malfunction of harness and connector

NO

Check and repair the self-diagnosis 
system with the MUT-

II

YES

Measure at A/T-ECU connector D-45



Disconnect the connector and measure at the harness side.



Voltage between terminals 5 and 14 and the earth
(ignition switch: ON)
OK: System voltage



Continuity between terminal 19 and earth
OK: Continuity

OK

Replace the A/T-ECU.

NG

OK

Check the trouble symptoms.

NG

Replace the A/T-ECU.

Is communication with other systems possible using the MUT-

II

?

NG

Repair

OK

Check the following connectors:
<L.H. drive vehicles> D-46, D-34, C-37, C-70, C-35
<R.H. drive vehicles> D-46, D-34, C-39, C-70, C-35

Check the trouble symptoms.

NG

Repair

OK

Check the following connectors:
<L.H. drive vehicles> D-45, C-24, C-78, C-74, D-34, C-68, C-72
<R.H. drive vehicles> D-45, C-26, C-78, C-74, D-34, C-68, C-72

Check the trouble symptoms

NG

Repair

OK



Check and repair the harness wire between the A/T-ECU
and the power supply.



Check and repair the harness wire between the A/T-ECU
and the earth.

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-11

INSPECTION PROCEDURE 14

Overdrive switch system

Probable cause

If downshifting does not occur when overdrive switch is turned off while driving
in 4th gear, or if shifting to 4th gear is not possible, the cause is probably a problem
in the overdrive switch system.



Malfunction of overdrive switch



Malfunction of harness or connector



Malfunction of A/T-ECU



Malfunction of ignition switch

*: Refer to ’00 PAJERO PININ Workshop Manual (Pub. No. CKRE00E1).

OK

Completed

NG

OK

Check the trouble symptoms.

Check the ignition switch. (Refer to GROUP 54 – Ignition Switch.)*

Replace the A/T-ECU.

NG

Repair

OK

MUT-

II

 SERVICE DATA



35  – Overdrive switch
OK: MUT-

II

 display and overdrive switch OD/OD-OFF posi-

tion should match.

NG

Repair

OK

Check the overdrive switch. (Refer to P.23-51.)*

NG

Measure at overdrive switch connector D-35.



Disconnect the connector and measure at the harness side



Voltage between terminal 3 and earth
(Ignition switch: ON)
OK: System voltage

Check the following connectors: D-35, D-34, D-46

NG

Repair

OK

Check the harness wire between the overdrive switch and the
A/T-ECU.

INSPECTION PROCEDURE 15

Stop lamp switch system

Probable cause

If large shocks occur during squat control, the cause is probably a problem with
the stop lamp switch.



Malfunction of stop lamp switch



Malfunction of harness or connector



Malfunction of A/T-ECU

*: Refer to ’00 PAJERO PININ Workshop Manual (Pub. No. CKRE00E1).

OK

Check the stop lamp switch 
(Refer to GROUP 35 – Brake Pedal)*

NG

NG

Repair

OK

OK

Check the trouble symptoms.

Replace the A/T-ECU.

MUT-

II

 SERVICE DATA



28  – Stop lamp switch
OK: ON when the brake pedal is depressed and OFF when

the brake pedal is released

Check the following connectors:
<L.H. drive vehicles> C-04, C-02, C-29, C-24, D-02, D-45
<R.H. drive vehicles> C-04, C-02, C-41, D-02, D-45

OK

NG

Repair

Check the harness wire between the stop lamp switch and the
A/T-ECU.

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-12

SERVICE DATA REFERENCE TABLE

Item No. 37 has been changed since the A/T-ECU has been changed. The other SERVICE DATA are
the same as before.

Item
No.

Inspection item

Inspection conditions

Normal value

37

Inhibitor switch

Ignition switch: ON
Engine: Stopped

Selector lever position: P

P

Engine: Stopped

Selector lever position: R

R

Selector lever position: N

N

Selector lever position: D

D

Selector lever position: 2

2

Selector lever position: L

L

A/T-ECU TERMINAL VOLTAGE REFERENCE CHART

Terminal
No.

Inspection item

Inspection conditions

Standard value

1

Solenoid valve No. 1

When in 1st or 2nd gear

System voltage

When in 3rd or 4th gear

0 V

2

Solenoid valve No. 2

When in 2nd or 3rd gear

System voltage

When in 1st or 4th gear

0 V

3

Free-wheeling engage
switch

Transfer lever position: Other than 4WD

System voltage

switch

Transfer lever position: 4WD

0 V

5

Back-up power supply

Ignition switch: OFF

System voltage

6

Solenoid valve No. 3

When lockup clutch is operating

System voltage

When lockup clutch is not operating

0 V

11

Communication with input
signals from engine-ECU

Engine: Idling
Selector lever position: D

Other than 0 V

13

A/T fluid temperature
sensor

ATF temperature: 120



C

Approx. 0.3 V

sensor

ATF temperature: 150



C

Approx. 0.15 V

14

Power supply

Ignition switch: OFF

0 V

Ignition switch: ON

System voltage

17

Communication with output
signals to engine-ECU

Engine: Idling
Selector lever position: D

Other than 0 V

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-13

Terminal
No.

Standard value

Inspection conditions

Inspection item

18

Stop lamp switch

Brake pedal: Depressed

System voltage

Brake pedal: Released

0 V

19

Earth

Engine: Idling

0 V

20

A/T fluid temperature
sensor earth

–

–

21

Diagnostic output terminal

–

–

23

Input shaft speed sensor

Ignition switch: OFF

0 V

Ignition switch: ON

2.5 V

24

Output shaft speed sensor

Vehicle: Stopped

Approx. 2.5 V

Vehicle: Driving

Other than 2.5 V

25

Overdrive switch

Overdrive switch: ON

System voltage

Overdrive switch: OFF

0 V

26

Inhibitor switch P

Selector lever position: P

System voltage

Selector lever position: Other than P

0 V

27

Inhibitor switch R

Selector lever position: R

System voltage

Selector lever position: Other than R

0 V

30

Input shaft speed sensor
earth

–

–

31

Output shaft speed sensor
earth

–

–

33

Wide open throttle switch

Accelerator pedal: Released

4.5 – 5.5 V

Accelerator pedal: Depressed

Less than 0.4 V

34

Dual-pressure switch

A/C switch: OFF

0 V

A/C switch: ON

System voltage

37

N range lamp

Ignition switch: ON

System voltage

Ignition switch: OFF

0 V

38

Inhibitor switch N

Selector lever position: N

System voltage

Selector lever position: Other than N

0 V

39

Inhibitor switch D

Selector lever position: D

System voltage

Selector lever position: Other than D

0 V

41

Diagnosis control terminal

–

–

42

Accelerator pedal position
sensor (power supply

Ignition switch: ON

Approx. 5 V

sensor (power supply
voltage)

Ignition switch: OFF

0 V