Mitsubishi Pajero Pinin. Manual - part 177

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-18

INSPECTION PROCEDURE 3

Does not move forward only

Probable cause

When the engine is idling, the vehicle does not move forward even if the selector
lever is shifted from N to D, 2 or L range. In such cases, the cause is probably
a malfunction of the clutch or brake.

D

Malfunction of forward clutch

D

Malfunction of direct clutch

D

Malfunction of one-way clutch No. 2

D

Malfunction of brake No. 1, No. 2, No. 3

D

Malfunction of A/T-ECU

L

: Refer to the Transmission Workshop Manual.

Does not vehicle move forward in D,
2 and L range?

No

Check the forward clutch. 

L

Yes

Does not vehicle move forward in D
and 2 range?

No

Check one-way clutch No. 2. 

L

Yes

Does not vehicle move forward in 2
range?

No

Check the brake No. 3. 

L

Yes

Which is the drive gear in D range?

2nd

Check the brake No. 1, No. 2. 

L

3rd

Check the direct clutch. 

L

Check the trouble symptoms.

NG

Replace the A/T-ECU.

INSPECTION PROCEDURE 4

Does not reverse only

Probable cause

When the engine is idling, the vehicle does not reverse even if the selector lever
is shifted from N to R range. In such cases, the cause is probably a malfunction
of a clutch, brake or the valve body.

D

Malfunction of brake No. 1, No. 3

D

Malfunction of direct clutch

D

Malfunction of valve body

D

Malfunction of planetary gear

D

Malfunction of A/T-ECU

L

: Refer to Transmission Workshop Manual.

Check the drive gear in D range.

2nd

Check the brake No. 1. 

L

1st

3rd

Check the planetary gear. 

L

Does the A/T shift up to 2nd gear?

No

Malfunction of 1-2 shift valve. 

L

Yes

Is there any slippage in 3rd gear in
D range?

NG

Check the direct clutch. 

L

OK

Check the brake No. 3. 

L

Check the trouble symptoms.

NG

Replace the A/T-ECU.

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-19

INSPECTION PROCEDURE 5

Upshifting does not occur

Probable cause

Upshifting does not occur under conditions when upshifting should occur. Check
shifting from 1

→

2, 2

→

3 and 3

→

4 respectively.

D

Malfunction of solenoid valve No. 1, No. 2

D

Malfunction of A/T-ECU

D

Malfunction of power train internal parts

L

: Refer to the Transmission Workshop Manual.

Is a normal diagnostic code output?

No

To Inspection Chart For Each Diagnosis
Code (Refer to P. 23-9.)

Yes

Does not the A/T shift from 1

→

2?

No

Does the A/T shift to 2nd gear in 2
range?

No

Malfunction of 1-2 shift valve. 

L

Malfunction of solenoid valve No.
2.

L

Yes

Yes

Check the brake No. 2 system. 

L

Check one-way clutch No. 1.

L

Does not the A/T shift from 2

→

3?

No

Does the vehicle reverse in R range?

No

Check the direct clutch system.

L

Yes

Yes

Malfunction of 2-3 shift valve.

L

Malfunction of solenoid valve No. 1.

L

A/T does not shift from 3

→

4.

Does the vehicle move in 1st gear in
D range?

No

Malfunction of solenoid valve No.
2. 

L

Yes

Inspection Procedure 15 – Overdrive
Switch System (Refer to P. 23-25.)

NG

Repair

OK

Malfunction of 3-4 shift valve. 

L

Check the trouble symptoms.

NG

Replace the A/T-ECU.

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-20

INSPECTION PROCEDURE 6

Downshifting does not occur

Probable cause

Downshifting does not occur under conditions when downshifting should occur. Check
shifting from 2

→

1, 3

→

2 and 4

→

3 respectively.

D

Malfunction of solenoid No. 1, No. 2

D

Malfunction of A/T-ECU

D

Malfunction of power train internal parts

L

: Refer to the Transmission Workshop Manual.

Is a normal diagnosis code output?

No

To Inspection Chart For Diagnosis
Code (Refer to P. 23-9.)

Yes

Does not the A/T shift from 4

→

3?

No

Which gear is engaged when the A/T
is shifted from D range to 2 range 
(accelerator OFF) while in 3rd gear?

(DRIVE 1ST)

Malfunction of solenoid valve No.
2 

L

Yes

(DRIVE 2ND, 4TH)

Malfunction of 3-4 shift valve 

L

Does not the A/T shift from 3

→

2?

No

Does the vehicle move in 1st gear in
D range?

(DRIVE 4TH)

Malfunction of 2–3 shift valve 

L

Yes

(DRIVE 1ST)

Malfunction of solenoid valve No. 1 

L

A/T does not shift from 2

→

1.

Does the A/T shift from 3

→

4 in D range?

No

Malfunction of solenoid valve No.
2 

L

Yes

Does the vehicle move forward in L
range?

No

Malfunction of 1–2 shift valve 

L

Yes

Does the vehicle reverse in R range?

No

Check the brake No. 1. 

L

Yes

Check the brake No. 2. 

L

Check the trouble symptoms.

NG

Replace the A/T-ECU.

INSPECTION PROCEDURE 7

Shifting point abnormality

Probable cause

Shifting occurs at points which are different from the shift pattern. Note that the
shift pattern will vary in different modes and at high A/T fluid temperatures.

D

Malfunction of A/T fluid temperature sensor

D

Malfunction of A/T-ECU

Is a normal diagnosis code output?

No

To Inspection Chart For Diagnosis
Code (Refer to P. 23-9.)

Yes

MUT-

II

 SERVICE DATA

D

15 – A/T fluid temperature sensor
OK: 70 – 90

_

C after engine

warmed-up

NG

Code No. 15, 16 – A/T fluid temperature
sensor system (Refer to P. 23-10.)

OK

Replace the A/T-ECU.

AUTOMATIC TRANSMISSION – 

Troubleshooting <A/T>

23-21

INSPECTION PROCEDURE 8

Upshifting occurs spontaneously

Probable cause

Upshifting occurs in ranges where upshifting should not occur, e. g. upshifting to
2nd gear in L range, 3rd gear in 2 range or 4th gear in D range when overdrive
is disconnected.

D

Malfunction of inhibitor switch

D

Malfunction of overdrive switch

D

Malfunction of A/T-ECU

MUT-

II

 SERVICE DATA

D

37 – Inhibitor switch
OK: MUT-

II

 display and selector

lever position should match

NG

Inspection Procedure 14 – Inhibitor
switch system (Refer to P. 23-25.)

OK

MUT-

II

 SERVICE DATA

D

35 – Overdrive switch
OK: MUT-

II

 display and mode 

selected should match

NG

Inspection Procedure 15 – Overdrive
switch system (Refer to P. 23-25.)

OK

Replace the A/T-ECU.

INSPECTION PROCEDURE 9

Incorrect drive gear position

Probable cause

Vehicle starts off in 2nd, 3rd or 4th gear when in D range. Often occurs when starting
off is not smooth.

D

Malfunction of inhibitor switch

D

Malfunction of direct clutch

D

Malfunction of planetary gear

D

Malfunction of valve body

D

Malfunction of forward clutch

D

Malfunction of solenoid valve No. 1

D

Malfunction of A/T-ECU

L

: Refer to the Transmission Workshop Manual.

MUT-

II

 SERVICE DATA

D

37 – Inhibitor switch
OK: MUT-

II

 display and selector

lever position should match

NG

Inspection Procedure 14 – Inhibitor
switch system (Refer to P. 23-25.)

OK

Does the vehicle move forward in 2nd
gear?

Yes

Inspection Procedure 6 – Downshifting
does not occur (Refer to P. 23-20.)

No

Does the vehicle move forward in 3rd
gear? (D range)

Yes

Does the vehicle reverse in R range?

Yes

Check the direct clutch. 

L

No

No

Check the planetary gear. 

L

Does the vehicle move forward in 3rd
gear? (2, L range)

Yes

Malfunction of 2–3 shift valve 

L

Malfunction of solenoid valve No. 1

L

No

Does the vehicle move forward in 4th
gear?

Yes

Does the vehicle reverse in R range?

Yes

Malfunction of solenoid valve No.
1 

L

No

No

Check the forward clutch. 

L

Malfunction of 2–3 shift valve 

L

Check the trouble symptoms.

NG

Replace the A/T-ECU.