Mitsubishi Grandis. Manual - part 957

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-153

<RH drive vehicles>

OPERATION

TCL/ASC-ECU terminal 38 is earthed every time the 
TCL switch is pressed. TCL/ASC-ECU monitors this 
operation state and turns the TCL system ON or 
OFF.

COMMENT

The cause is probably an open-circuit in the TCL 
switch circuit.

PROBABLE CAUSES

• Malfunction of the TCL switch

• Damaged harness, connector

• Malfunction of the TCL/ASC-ECU

TCL OFF 
SWITCH

COMBINATION
METER

TCL/ASC-ECU

FRONT-ECU
TAIL LAMP 
RELAY

RELAY 
BOX

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

TCL Switch Circuit

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-154

DIAGNOSIS

STEP 1. Voltage measurement at TCL/ASC-ECU 
connector A-04.

(1) Disconnect the connector A-04, and connect 

special tool ABS Check Harness (MB991997) to 
the wiring harness-side connector.
NOTE: Do not connect special tool ABS Check 
Harness (MB991997) to the TCL/ASC-ECU.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the terminal voltage between special 

tool MB991997 connector terminal 38 
(TCL/ASC-ECU connector A-04 terminal 38) and 

earth.

OK:

• When the TCL switch is not pressed, 

the voltage should measure battery 
positive voltage (approximately 12 
volts).

• When the TCL switch is pressed, the 

voltage should measure 1 volt or less. 

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

position.

(5) Disconnect special tool MB991997 between the 

TCL/ASC-ECU and the body-side harness 
connector.

(6) Connect all the connectors from the 

TCL/ASC-ECU.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Go to Step 2.

STEP 2. Check the TCL switch.
(1) Remove the TCL switch. (Refer to 

P.35C-163

).

(2) Connect an ohmmeter to the TCL switch between 

terminals 1 and 2.

(3) Check for continuity between terminals 1 and 2 

when the TCL switch is operated.

OK:

• There is no continuity between 

terminals 1 and 2 when the TCL 
switch is not pressed.

• There is continuity between terminals 

1 and 2 when the TCL switch is 
pressed.

Q: Is the check result normal?

YES : 

Install the TCL switch. (Refer to 

P.35C-163

). Then go to Step 6.

NO : 

Replace the TCL switch. (Refer to 

P.35C-163

). Then go to Step 7.

AC312620AQ

Oil reservoir

Connector: A-04

TCL/ASC-ECU

MB991997

Check connector

A-04 Harness connector

A-04

Hydraulic unit
(with built-in TCL/ASC-ECU)

AC313229AB

C-28 TCL switch
connector

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-155

STEP 3. Check TCL/ASC-ECU connector A-04, 
intermediate connector C-124 and TCL switch 
connector C-28 for loose, corroded or damaged 
terminals, or terminals pushed back in the 
connector.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair or replace the faulty connector. Then 
go to Step 7.

STEP 4. Check the harness wire between 
TCL/ASC-ECU connector A-04 terminal 38 and 
TCL switch connector C-28 terminal 1 for 
damage.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the damaged harness wire. Then go 
to Step 7.

AC312621

Oil reservoir

Connector: A-04

AB

A-04

Hydraulic unit
(with built-in TCL/ASC-ECU)

A-04 Harness connector
(harness side)

AC312624AG

Connectors: C-28, C-124
<L.H.drive vehicles>

C-28

C-124

C-124

C-28

AC312625AG

Connectors: C-28, C-124
<R.H.drive vehicles>

C-124

C-124

C-28

C-28

AC312621

Oil reservoir

Connector: A-04

AB

A-04

Hydraulic unit
(with built-in TCL/ASC-ECU)

A-04 Harness connector
(harness side)

AC312624 AH

Connector: C-28
<L.H.drive vehicles>

C-28

C-28 Harness connector
(harness side)

AC312625AH

Connector: C-28
<R.H.drive vehicles>

C-28

C-28 Harness connector
(harness side)

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-156

STEP 5. Check the harness wire between TCL 
switch connector C-28 terminal 2 and earth for 
damage.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the damaged harness wire. Then go 
to Step 7.

STEP 6. Retest the system

Q: Is TCL system cancelled when the TCL switch is 

push on?

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.00-5

).

NO : 

Replace the hydraulic unit (integrated with 
TCL/ASC-ECU). Then go to Step 7.

STEP 7. Retest the system

Q: Does TCL system cancelled, when the TCL switch 

is push on?

YES : 

The procedure is complete.

NO : 

Return to Step 1.

INSPECTION PROCEDURE 11: TCL/ASC System dose not Operate.

COMMENT

The fail-safe function is probably canceling TCL/ASC 
system. In this case, MUT-III can be used to Retest 
each system by checking the diagnosis codes.

PROBABLE CAUSES

• Malfunction of the CAN bus line.

• Malfunction of the TCL/ASC-ECU.

• Battery voltage low.

DIAGNOSIS

STEP 1. Hydraulic unit check
 Refer to 

P.35B-75

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Connect the brake pipes correctly, repair the 
external brake lines, or replace the hydraulic 
unit.

STEP 2. Verify that the condition described by 
the customer exists.

Q: Can any faults be found with the brake operation?

YES : 

Check the brake system related 

components except the ASC system.

NO : 

The procedure is complete.

DATA LIST REFERENCE TABLE

M1355001500023

The following items can be read by the MUT-III from 
the TCL/ASC-ECU input data.

AC312624 AH

Connector: C-28
<L.H.drive vehicles>

C-28

C-28 Harness connector
(harness side)

AC312625AH

Connector: C-28
<R.H.drive vehicles>

C-28

C-28 Harness connector
(harness side)