Continuously Variable Transmission/Transaxle, CVT

DTC U0121: CAN Time-out Error (ABS)

DIAGNOSTIC FUNCTION

TCM determines that malfunction is present if the periodic communication data sent from the ABS-ECU via CAN bus lines is abnormal.

JUDGMENT CRITERIA

TCM cannot receive the periodic communication data from ABS-ECU.

PROBABLE CAUSES

- Malfunction of the CAN bus
- ABS-ECU malfunction
- Malfunction of TCM

DIAGNOSTIC PROCEDURE

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

Use scan tool MB991958 to perform the CAN bus diagnosis.

Q. Is the check result normal?

YES Go to Step 2.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart).
STEP 2. Scan tool diagnostic trouble code

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

Q. Is the ABS-related diagnostic trouble code set?

YES Carry out the appropriate troubleshooting.
NO Go to Step 3.
STEP 3. Symptom recheck after erasing diagnostic trouble code

Q. Is the check result normal?

YES Intermittent malfunction
NO Replace TCM.