DTC U0121: ASC Time-out Error: Diagnosis
- STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics
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Use scan tool (M.U.T.-IIISE) to perform the CAN bus diagnosis.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTICS TABLE ).
- STEP 2. Check for DTC of other systems
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Check whether an ASC "time-out" related DTC is set in other ECUs (Refer to CAN-RELATED DIAGNOSTIC TROUBLE CODE TABLE ).
Q: Is the DTC set?
YES: Go to Step 3.
NO: Go to Step 4.
- STEP 3. Check whether the DTC is set again
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Check again if the DTC is set.
- Erase the DTC.
- Turn the ignition switch to the LOCK (OFF) position.
- Turn the ignition switch to the ON position.
- Check if the DTC is set.
Q: Is the DTC U0121 set?
YES: Replace the hydraulic unit (ASC-ECU) (Refer to HYDRAULIC UNIT ).
NO: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
- STEP 4. Check whether the DTC is set again
.
Check again if the DTC is set.
- Erase the DTC.
- Turn the ignition switch to the LOCK (OFF) position.
- Turn the ignition switch to the ON position.
- Check if the DTC is set.
Q: Is the DTC U0121 set?
YES: Replace the AWC-ECU (Refer to AWC-ECU <AWD> ).
NO: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).