Shift Lever

DTC U0121: ASC Time-out Error

CAUTION:

- If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

JUDGMENT CRITERIA

The periodic communication data from the ASC-ECU cannot be received.

PROBABLE CAUSES

- The CAN bus line is defective.
- Malfunction of ASC-ECU
- Malfunction of the shift lever-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics

Using the scan tool, diagnose the CAN bus lines.

Q. Is the check result normal?

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

Check the ASC diagnostic trouble code. Active Stability Control System (ASC).)

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 3.
STEP 3. Check whether the DTC is reset.

Q. Is DTC No. U0121 set?

YES Replace the shift lever assembly. (Refer to Service and Repair.)
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)