Code No. U0121: CAN Time-out Error (ABS/ASC)


DIAGNOSTIC FUNCTION


The CVT-ECU determines that the system is defective if the ECU can receive no CAN communication information from the ABS-ECU/ASC-ECU.

JUDGEMENT CRITERIA


No information is received from the ABS-ECU/ASC-ECU for 2.5 seconds.

PROBABLE CAUSES



DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to perform the CAN bus diagnosis.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Diagnosis Code Chart ).

STEP 2. M.U.T.-III diagnosis code
Check if the ABS/ASC related diagnosis code is set.

Q. Is the ABS/ASC-related diagnosis code set?
Carry out the appropriate troubleshooting.
Go to Step 3.

STEP 3. M.U.T.-III diagnosis code
Is diagnosis code No. U0121 set in the other ECU, which communicates with the ABS-ECU/ASC-ECU via CAN?

Q. Is the diagnosis code set?
Go to Step 4.
Go to Step 5.

STEP 4. Symptom recheck after erasing diagnosis code

Q. Is the diagnosis code set?
Replace ABS-ECU/ASC-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).

STEP 5. Symptom recheck after erasing diagnosis code

Q. Is the diagnosis code set?
Replace CVT-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).