Mitsubishi Grandis. Manual - part 848

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-59

STEP 10. Check the harness between inhibitor 
switch connector B-111 terminal No.1 and shift 
switch assembly connector C-121 terminal No.1.

Check the output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the wiring harness.

Code No.28: Inhibitor switch system

INHIBITOR SWITCH SYSTEM CIRCUIT

 Refer to 

P.23A-52

.

OPERATION

 Refer to 

P.23A-52

.

DIAGNOSIS CODE SET CONDITIONS

If the inhibitor switch has been sending multiple 
signals for at least 30 seconds, the circuit may be 
open and diagnosis code No.28 will be set.

POSSIBLE CAUSES

• Malfunction of the inhibitor switch

• Damaged harness wires and connectors

• Malfunction of the engine-A/T-ECU

DIAGNOSIS

STEP 1. Check the inhibitor switch.

Refer to 

P.23A-128

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Replace the inhibitor switch.

AC303714AH

Connector: B-111

B-111 (B)

Harness side

AC310613

BA

C-121

Connector: C-121
<LHD>

Harness side

AC310631AW

C-121

Harness side

Connector: C-121
<RHD>

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-60

STEP 2. Connector check: B-111 Inhibitor switch 
connector, C-112 engine-A/T-ECU connector

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the defective connector.

STEP 3. Check the harness between inhibitor 
switch connector B-111 terminal No.3, 7, 4, 1 and 
engine-A/T-ECU connector C-112 terminal No.66, 
67, 75, 76.

Check the output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

AC303714AH

Connector: B-111

B-111 (B)

Harness side

AC311284

Connector: C-112 <LHD>

Connector: C-112 <RHD>

Harness side

Engine-A/T-ECU

C-112 (GR)

C-112 (GR)

Engine-A/T-ECU

AG

AC303714AH

Connector: B-111

B-111 (B)

Harness side

AC311284

Connector: C-112 <LHD>

Connector: C-112 <RHD>

Harness side

Engine-A/T-ECU

C-112 (GR)

C-112 (GR)

Engine-A/T-ECU

AG

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-61

STEP 4. Connector check: C-121 shift switch 
assembly connector, C-17 intermediate 
connector

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the defective connector.

STEP 5. Check the harness between inhibitor 
switch connector B-111 terminal No.1 and shift 
switch assembly connector C-121 terminal No.1.

Check the output line for short circuit.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 6. MUT-III data list

Item 61: Inhibitor switch (Refer to data list reference 
table 

P.23A-117

).

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-5

).

NO : 

Replace the engine-A/T-ECU.

AC310613

BA

C-121

Connector: C-121
<LHD>

Harness side

AC310631AW

C-121

Harness side

Connector: C-121
<RHD>

AC310615

AR

Connector: C-17
<LHD>

C-17

AC310628

Connector: C-17
<RHD>

AV

C-17

AC303714AH

Connector: B-111

B-111 (B)

Harness side

AC310613

BA

C-121

Connector: C-121
<LHD>

Harness side

AC310631AW

C-121

Harness side

Connector: C-121
<RHD>

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-62

Code No.31: Low-reverse solenoid valve system

OPERATION

• Solenoid valve closes or opens according to the 

signals from the engine-A/T-ECU.

BATTERY

RELAY
BOX

A/T
CONTROL
RELAY

A/T CONTROL
SOLENOID
VALVE ASSEMBLY

ENGINE-
A/T-ECU

UNDERDRIVE
SOLENOID
VALVE

SECOND
SOLENOID
VALVE

OVERDRIVE
SOLENOID
VALVE

DAMPER 
CLUTCH 
CONTROL 
SOLENOID 
VALVE

LOW AND
REVERSE
SOLENOID
VALVE

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Gray     R : Red     P : Pink     V : Violet   

Solenoid valve system circuit