Mitsubishi Galant (2004+). Manual - part 1520

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-21

STEP 5. Recheck for diagnostic trouble code.

Check again if the DTC is set.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTC (Refer to 

P.13D-4

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Turn the ignition switch to the "ON" position.
(6) Check if the DTC is set.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
(8) Disconnect scan tool MB991958.
Q: Is DTC U1101 set?

YES : Replace the hydraulic unit (integrated with 

ABS/TCL-ECU) (Refer to GROUP 35B - Hydraulic 
Unit 

P.35B-109

). Then go to Step 6 .

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.00-6

.

STEP 6. Recheck for diagnostic trouble code.

Check again if the DTC is set.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTC (Refer to 

P.13D-4

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Turn the ignition switch to the "ON" position.
(6) Check if the DTC is set.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
(8) Disconnect scan tool MB991958.
Q: Is DTC U1101 set?

YES : Return to Step 1 .
NO :  The procedure is complete.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-22

U1120 CAN Communications System TCL Uncontrollable by Engine Malfunction

CAUTION

• If DTC U1120 is set in the ABS/TCL-ECU, 

always diagnose the CAN main bus line. If 
there is any fault in the CAN bus lines, an 
incorrect DTC may be set.

• Whenever the ECU is replaced, ensure that 

the communication circuit is normal.

CAUTION

The engine control system-related DTC may be 
set when DTC U1120 is set. (For details refer to 
GROUP 00, Intersystem Affiliated DTC Reference 
Table 

P.00-16

). Diagnose the engine control sys-

tem first when the engine control system-related 
DTC is set.

.

DTC SET CONDITION
The ABS/TCL-ECU receives engine system-related 
signals from the powertrain control module (PCM) 
via CAN bus lines. If a fail-safe related data is con-
tained in the signal from the PCM, DTC U1120 will be 
stored.

.

TROUBLESHOOTING HINTS (The most likely 
causes for these DTCs are to set are:)

• Damaged harness or connector.

• Malfunction of the PCM.

• Malfunction of the ABS/TCL-ECU.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: MUT-III USB cable

• MB991910: MUT-III main harness A

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Check for MFI system diagnostic trouble code (Refer to 

GROUP 13B, MFI Diagnosis - How to Read and Erase 
Diagnostic Trouble Code 

P.13B-5

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect scan tool MB991958.
Q: Is any DTC set?

YES : Repair the MFI control system. (Refer to GROUP 

13B, MFI Diagnosis 

− Diagnostic Trouble Code Chart 

P.13B-33

). Then go to Step 6 .

NO :  Go to Step 2 .

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-23

STEP 2. Using scan tool MB991958, diagnose the CAN bus 
line.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

P.13D-4

.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line. (refer to GROUP 54C, 

Diagnostic Trouble Code Diagnosis - How to Diagnose the 
CAN Bus Line 

P.54C-12

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect scan tool MB991958.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 3 .
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-14

). Then go to Step 6 .

STEP 3. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Check if a DTC, which relates to CAN 

communication-linked systems below, is set.
A/C-ECU

• DTC U1120: Failure Information on Power train con-

trol module (related to engine)

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect scan tool MB991958.
Q: Is DTC U1120 set?

YES : Go to Step 4 .
NO :  Go to Step 5 .

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS

TSB Revision

TRACTION CONTROL SYSTEM (TCL)

13D-24

STEP 4. Recheck for diagnostic trouble code.

Check again if the DTC is set.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTC (Refer to 

P.13D-4

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Turn the ignition switch to the "ON" position.
(6) Check if the DTC is set.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
(8) Disconnect scan tool MB991958.
Q: Is DTC U1120 set?

YES : Replace the PCM [Refer to GROUP 13B, Power 

Control Module (PCM) 

P.13B-1146

]. Then go to Step 

6 .

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.00-6

.

STEP 5. Recheck for diagnostic trouble code.

Check again if the DTC is set.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector 

(Refer to 

P.13D-4

).

(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTC (Refer to 

P.13D-4

).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Turn the ignition switch to the "ON" position.
(6) Check if the DTC is set.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
(8) Disconnect scan tool MB991958.
Q: Is DTC U1120 set?

YES : Replace the hydraulic unit (integrated with 

ABS/TCL-ECU) (Refer to GROUP 35B - Hydraulic 
Unit 

P.35B-109

). Then go to Step 6 .

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.00-6

.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827