Mitsubishi Evolution X. Manual - part 358

DIAGNOSIS <S-AWC(SUPER ALL WHEEL CONTROL)>

TSB Revision

MANUAL TRANSAXLE

22A-81

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C 

− 

Troubleshooting 

P.54C-14

.) After repairing the CAN 

bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.
Q: Is DTC No. U0001 set?

YES : Replace the AWC-ECU.(Refer to 

P.22A-132

.) Then 

go to Step 3.

NO :  Intermittent malfunction. (Refer to GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 3. Check whether the DTC is reset.
Q: Is DTC No. U0001 set?

YES : Return to Step 1.
NO :  This diagnosis is complete.

DTC U0100: Engine Time-out Error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

.

OPERATION

AWC-ECU communicates with the engine control 
module via the CAN bus lines.

.

DTC SET CONDITIONS

The code is set when the signal sent from the engine 
ECU cannot be received for a certain period.

.

PROBABLE CAUSES

• The CAN bus line is defective.

• Malfunction of engine control module

• Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C 

− 

Troubleshooting 

P.54C-14

.) After repairing the CAN 

bus line, go to Step 2.

DIAGNOSIS <S-AWC(SUPER ALL WHEEL CONTROL)>

TSB Revision

MANUAL TRANSAXLE

22A-82

STEP 2. Scan tool diagnostic trouble code
Check the engine diagnostic trouble code. (Refer to GROUP 
13A 

− Troubleshooting 

P.13A-44

.)

Q: Is the DTC set?

YES : Perform the relevant troubleshooting.
NO :  Go to Step 3.

STEP 3. Check whether the DTC is reset.
Q: Is DTC No. U0100 set?

YES : Replace the AWC-ECU.(Refer to 

P.22A-132

.) Then 

go to Step 4.

NO :  Intermittent malfunction. (Refer to GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 4. Check whether the DTC is reset.
Q: Is DTC No. U0100 set?

YES : Return to Step 1.
NO :  This diagnosis is complete.

DTC U0101: TC-SST Time-out Error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

.

OPERATION

AWC-ECU communicates with TC-SST-ECU via the 
CAN bus lines.

.

DTC SET CONDITIONS

The code is set when the signal sent from the 
TC-SST-ECU cannot be received for a certain 
period.

.

PROBABLE CAUSES

• The CAN bus line is defective.

• Malfunction of TC-SST-ECU

• ETACS coding data error

• Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C 

− 

Troubleshooting 

P.54C-14

.)

STEP 2. Scan tool diagnostic trouble code
Check the TC-SST diagnostic trouble code. (Refer to GROUP 
22C 

− Troubleshooting 

P.22C-10

.)

Q: Is the DTC set?

YES : Perform the relevant troubleshooting.
NO :  Go to Step 3.

DIAGNOSIS <S-AWC(SUPER ALL WHEEL CONTROL)>

TSB Revision

MANUAL TRANSAXLE

22A-83

STEP 3. ETACS-ECU coding data check
Check the transaxle coding data stored in ETACS-ECU for any 
abnormality. (Refer to GROUP 00 

− Coding Reference Table 

P.00-39

.)

Q: Is the check result normal?

YES : Go to Step 4.
NO :  Replace the ETACS-ECU. (Refer to GROUP 54A 

− 

ETACS-ECU 

P.54A-676

.) Then go to Step 5.

STEP 4. Check whether the DTC is reset.
Q: Is DTC No. U0101 set?

YES : Replace the AWC-ECU.(Refer to 

P.22A-132

.) Then 

go to Step 5.

NO :  Intermittent malfunction. (Refer to GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 5. Check whether the DTC is reset.
Q: Is DTC No. U0101 set?

YES : Return to Step 1.
NO :  This diagnosis is complete.

DTC U0121: ASC Time-out Error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

.

OPERATION

AWC-ECU communicates with the ASC-ECU via the 
CAN bus lines.

.

DTC SET CONDITIONS

The code is set when the signal sent from the 
ASC-ECU cannot be received for a certain period.

.

PROBABLE CAUSES

• The CAN bus line is defective.

• Malfunction of ASC-ECU

• Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C 

− 

Troubleshooting 

P.54C-14

.)

DIAGNOSIS <S-AWC(SUPER ALL WHEEL CONTROL)>

TSB Revision

MANUAL TRANSAXLE

22A-84

STEP 2. Scan tool diagnostic trouble code
Check the ASC diagnostic trouble code. (Refer to GROUP 35C 
− Troubleshooting 

P.35C-20

.)

Q: Is the DTC set?

YES : Perform the relevant troubleshooting.
NO :  Go to Step 3.

STEP 3. Check whether the DTC is reset.
Q: Is DTC No. U0121 set?

YES : Replace the AWC-ECU. (Refer to 

P.22A-132

.) Then 

go to Step 4.

NO :  Intermittent malfunction. (Refer to GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 4. Check whether the DTC is reset.
Q: Is DTC No. U0121 set?

YES : Return to Step 1.
NO :  This diagnosis is complete.

DTC U0126: Steering Wheel Sensor Time-out Error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnostic trouble code may be 
set. Prior to this diagnosis, diagnose the CAN 
bus lines.

• Whenever the ECU is replaced, ensure that 

the CAN bus lines are normal.

• When the steering wheel sensor is replaced, 

calibrate the steering wheel sensor (refer to 
GROUP 35C 

− On-vehicle Service 

P.35C-267

), 

and initialize the steering angle correction 
amount stored in AWC-ECU. (Item No.09: 
Steering angle correction amount initializa-
tion 

P.22A-113

.)

.

OPERATION

AWC-ECU communicates with the steering wheel 
sensor via the CAN bus lines.

.

DTC SET CONDITIONS

The code is set when the signal sent from the steer-
ing wheel sensor cannot be received for a certain 
period.

.

PROBABLE CAUSES

• The CAN bus line is defective.

• Malfunction of steering wheel sensor

• Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C 

− 

Troubleshooting 

P.54C-14

.)