Code No. U0100: Engine CAN Timeout

  • If there is any problem in the CAN bus lines, an incorrect diagnosis 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.


ACC/FCM-ECU communicates with the engine-ECU via the CAN bus lines.


This diagnosis code is set when the abnormality below is detected:



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 ).

STEP 2. M.U.T.-III other system diagnosis code.

Check the engine diagnosis code (Refer to GROUP 13C -Troubleshooting <4J1>, 13D -Troubleshooting <4N1>).

Q. Is the diagnosis code set?

Perform the relevant troubleshooting.
Go to Step 3

STEP 3. M.U.T.-III other system diagnosis code.

Check if the diagnosis code No. U0100 is set to other ECU.

Q. Is the diagnosis code set?

Replace the engine-ECU (Refer to GROUP 13C - Engine-ECU <4J1>, GROUP 13D - Engine-ECU <4N1>).
Go to Step 4

STEP 4. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.U0100 set?

Replace the ACC/FCM-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).