Mitsubishi Galant (2004+). Manual - part 1523

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-33

.

CIRCUIT OPERATION
ABS/TCL-ECU terminal 6 is grounded every time the 
TCL switch is pressed. ABS/TCL-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.

.

TROUBLESHOOTING HINTS

• Malfunction of the TCL switch

• Damaged harness, connector

• Malfunction of the ABS/TCL-ECU

DIAGNOSIS

Required Special Tools:

• MB991223: Harness set

• MB991958: Scan tool (MUT-III sub assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

• MB991970: ABS check harness

AC305209AB

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

COMPONENT SIDE

AC305232AU

CONNECTORS: C-29, C-131

C-29

C-131(GR)

C-29 MALE SIDE

CONNECTOR

C-131 HARNESS

CONNECTOR:

COMPONENT SIDE

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-34

STEP 1. Measure the terminal voltage at ABS/TCL-ECU 
connector A-02.

(1) Disconnect all the connectors from the ABS/TCL-ECU.

(2) Connect special tool MB991970 between the 

ABS/TCL-EUC and the body-side harness connector.

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

MB991970 connector terminal 6 (ABS/TCL-ECU connector 
A-02 terminal 6) and ground.

• 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. 

(5) Turn the ignition switch to the "LOCK" (OFF) position.
(6) Disconnect special tool MB991970 between the 

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

(7) Connect all the connectors from the ABS/TCL-ECU.
Q: Is the terminal voltage battery terminal voltage when the 

TCL switch is not pressed, and is the terminal voltage 1 
volt or less when the TCL switch is pressed?
YES : Go to Step 6 .
NO :  Go to Step 2 .

AC305209AB

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

COMPONENT SIDE

AC307168

19

2

18

1

8

9

7

6

5

4

3

10

11   

25

15

16

17

27

28

26

12

13

14

23

24

22 21 20

AB

ABS/TCL-ECU

MB991970

BODY SIDE
HARNESS

SPECIAL TOOL
28-PIN CONNECTOR
(ABS/TCL-ECU CONNECTOR A-02)

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-35

STEP 2. Check the TCL switch.

(1) Remove the TCL switch (Refer to 

P.13D-47

).

(2) Connect an ohmmeter to the TCL switch between terminals 

1 and 2.

(3) Check the continuity between terminals 1 and 2 when the 

TCL switch is operated.

• 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 there no continuity between terminals 1 and 2 when 

the TCL switch is not pressed, and is there continuity 
when the TCL switch is pressed?
YES : Install the TCL switch (Refer to 

P.13D-47

). Then go to 

Step 6 .

NO :  Replace the TCL switch (Refer to 

P.13D-47

). Then go 

to Step 7 .

AC307176AB

C-131 TCL SWITCH

CONNECTOR

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-36

STEP 3. Check ABS/TCL-ECU connector A-02, 
intermediate connector C-29 and TCL switch connectors 
C-131 for loose, corroded or damaged terminals, or 
terminals pushed back in the connector.

Q: Are there connectors and terminals in good condition?

YES : Go to Step 4 .
NO :  Repair or replace the faulty connector (Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

). Then go to Step 7 .

AC305209AB

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

COMPONENT SIDE

AC305232AU

CONNECTORS: C-29, C-131

C-29

C-131(GR)

C-29 MALE SIDE

CONNECTOR

C-131 HARNESS

CONNECTOR:

COMPONENT SIDE