S-AWC
DTC U0001: Bus OffCAUTION
^ 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.
DTC SET CONDITIONS
The code is set when AWC-ECU ceases (bus-off).
PROBABLE CAUSES
^ The CAN bus line is defective.
^ Malfunction of AWC-ECU
^ ECU malfunction of other system
DIAGNOSTIC PROCEDURE
STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines. After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.
Q: Is DTC No. U0001 set?
YES: Replace the AWC-ECU. Then go to Step 3.
NO: Intermittent malfunction.
STEP 3. Check whether the DTC is reset.
Q: Is DTC No. U0001 set?
YES: Return to Step 1.
NO: This diagnosis is complete.