Mitsubishi Grandis. Manual - part 928

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-37

CAUTION

If there is any problem in the CAN bus lines, an 
incorrect diagnosis code may be set. Prior to this 
diagnosis, diagnose the CAN bus lines.

OPERATION

• The TCL/ASC-ECU contains the power supply 

circuit (terminal 32) for the solenoid valve. The 
solenoid valve is energized by the valve relay, 
which is incorporated in the TCL/ASC-ECU.

• The valve relay, which is incorporated in the 

TCL/ASC-ECU, is always energizing the solenoid 
valve unless the initial check is in progress when 
the ignition switch is turned on.

• The TCL/ASC-ECU activates the solenoid valve 

by turning on its driving transistor.

DIAGNOSIS CODE SET CONDITIONS

These diagnosis codes will be set under the cases 
below.

• The solenoid valve is not energized even after 

the TCL/ASC-ECU has turned on the driving 
transistor (Open circuit is present in the power 
supply circuit to the TCL/ASC-ECU solenoid 
valve, or the valve relay has failed).

• The solenoid valve is not energized even after 

the TCL/ASC-ECU has turned on the driving 
transistor (Open circuit is present in the solenoid 
valve circuit inside the TCL/ASC-ECU, or the 
valve relay has failed).

• After the TCL/ASC-ECU has turned off the driving 

transistor, the solenoid valve still remains 
energized (short in the solenoid valve circuit).

• When a solenoid valve failure is detected

PROBABLE CAUSES

The most likely causes for these diagnosis codes to 
set are:

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with 

TCL/ASC-ECU)

DIAGNOSIS

STEP 1. MUT-III CAN bus diagnostics.

CAUTION

Before connecting or disconnecting the MUT-III, 
turn the ignition switch to the "LOCK" (OFF) 
position.
(1) Connect MUT-III to the 16-pin diagnosis 

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is the check result?

YES : 

Go to Step 3.

NO : 

Repair the CAN bus line (Refer to GROUP 
54D, CAN bus line Diagnostic flow 

P.54D-9

). Then go to Step 2.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-38

STEP 2. Check whether the diagnosis code is 
reset.

CAUTION

Before connecting or disconnecting the MUT-III, 
turn the ignition switch to the "LOCK" (OFF) 
position.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF) 

position.

(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is code No.C1226, C1231, C1236, C1241, C1246, 

C1251, C1256, C1261, C1300, C1305, C1310 or 
C1315 set?

YES : 

Go to Step 3.

NO : 

The procedure is complete.

STEP 3. 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 voltage between terminal 32 and 

earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 4.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

AC312620AL

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)

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-39

STEP 4. Check TCL/ASC-ECU connector A-04 for 
loose, corroded or damaged terminals, or 
terminals pushed back in the connector.

Q: Is the check result normal?

YES : 

An open or short circuit may be present in 

the solenoid valve power supply circuit. 
Repair the wiring harness between 
TCL/ASC-ECU connector A-04 terminal 32 
and fusible link No.3. Then go to Step 8.

NO : 

Repair or replace the damaged 
component(s). Then go to Step 8.

STEP 5. Resistance 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) Measure the resistance between terminal 16 and 

earth.

OK: 2 ohm or less

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Go to Step 6.

AC312621

Oil reservoir

Connector: A-04

AB

A-04

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

A-04 Harness connector
(harness side)

AC312620AM

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)

TROUBLESHOOTING

TRACTION CONTROL/ACTIVE STABILITY CONTROL SYSTEM

35C-40

STEP 6. Check TCL/ASC-ECU connector A-04 for 
loose, corroded or damaged terminals, or 
terminals pushed back in the connector.

Q: Is the check result normal?

YES : 

An open circuit may be present in the earth 

circuit. Repair the wiring harness between 
TCL/ASC-ECU connector A-04 terminal 16 
and the body earth. Then go to Step 8  .

NO : 

Repair or replace the damaged 
component(s). Then go to Step 8.

STEP 7. Check whether the diagnosis code is 
reset.

Check again if the diagnosis code is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF) 

position.

(4) Turn the ignition switch to the "ON" position.
(5) Drive the vehicle at 20 km/h or more for 30 

seconds or   more.

(6) Check if the diagnosis code is set.
(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is code No.C1226, C1231, C1236, C1241, C1246, 

C1251, C1256, C1261, C1300, C1305, C1310 or 
C1315 set?

YES : 

Replace the hydraulic unit (integrated with 

TCL/ASC-ECU). Then go to Step 8.

NO : 

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

.

AC312621

Oil reservoir

Connector: A-04

AB

A-04

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

A-04 Harness connector
(harness side)

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824