DTC U0251: AWC time-out error (Local CAN); DTC U0440: AWC communication error (Local CAN); DTC U0435: AWC signal abnormality (Local CAN): Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827 M.U.T.-III USB Cable
- MB991910 M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Using scan tool MB991958, diagnose the CAN bus lines.

Q: Is the check result normal?

YES : Go to Step 3.

NO : Repair the CAN bus lines. (Refer to TROUBLESHOOTING .) After repairing the CAN bus line, go to Step 2.
STEP 2. DTC recheck after repairing the CAN bus line
Q: Are DTC U0251, U0440, and U0435 set?

YES : Go to Step 3.

NO : This diagnosis is complete.
STEP 3. Diagnostic trouble code check of other systems using scan tool MB991958
Using scan tool MB991958, check if a diagnostic trouble code is set in S-AWC-ECU.

Q: Is other DTC set?

YES : Troubleshoot the relevant diagnostic trouble code, and then go to Step 8.

NO : Go to Step 4.
STEP 4. Connector check: A-05 ASC-ECU connector, C-46 S-AWC-ECU connector, C-47 intermediate connector, C-50 joint connector
Q: Is the check result normal?

YES : Go to Step 5.

NO : Repair the connector, and then go to Step 8.
STEP 5. Wiring harness check between A-05 ASC-ECU connector terminal No. 18 and C-46 S-AWC-ECU connector terminal No. 9, between A-05 ASC-ECU connector terminal No. 19 and C-46 S-AWC-ECU connector terminal No. 10
- Open or short circuit check of communication circuit
Q: Is the check result normal?

YES : Go to Step 6.

NO : Repair the wiring harness, and then go to Step 8.
STEP 6. Check whether the DTC is reset.
Q: Are DTC U0251, U0440, and U0435 set?

YES : Replace the S-AWC-ECU. (Refer to AWC-ECU .) Then go to Step 7.

NO : Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)
STEP 7. Check whether the DTC is reset.
Q: Are DTC U0251, U0440, and U0435 set?

YES : Replace the hydraulic unit (incorporates in ASC-ECU).(Refer to HYDRAULIC UNIT .) Then go to Step 8.

NO : The procedure is complete.
STEP 8. Check whether the DTC is reset.
Q: Are DTC U0251, U0440, and U0435 set?

YES : Return to Step 1.

NO : The procedure is complete.