LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2020 >> Eclipse Cross ES, AWD >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Continuously Variable Transaxle (CVT) (With Diagnostics) >> Diagnosis <CVT> >> Diagnostic Trouble Code Procedures >> DTC U0121: CAN time-out error (ABS/ASC) >> Diagnosis
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0121: CAN time-out error (ABS/ASC): Diagnosis

  1. STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics  .

    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 ).

  2. STEP 2. Scan tool (M.U.T.-IIISE) diagnostic trouble code  .

    Check if the ASC-related diagnostic trouble code is set.

    Q: Is the ASC-related diagnostic trouble code set? 

    YES  : Carry out the appropriate troubleshooting.

    NO  : Go to Step  3.

  3. STEP 3. Scan tool (M.U.T.-IIISE) diagnostic trouble code  .

    Is diagnostic trouble code No. U0121 set in the other ECU, which communicates with the ASC-ECU via CAN?

    Q: Is the diagnostic trouble code set? 

    YES  : Go to Step  4.

    NO  : Go to Step  5.

  4. STEP 4. Symptom recheck after erasing diagnostic trouble code  .

    Q: Is the diagnostic trouble code set? 

    YES  : Replace the ASC-ECU.

    NO  : Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

  5. STEP 5. Symptom recheck after erasing diagnostic trouble code  .

    Q: Is the diagnostic trouble code set? 

    YES  : Replace the TCM.

    NO  : Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).