Code No.U0401: Engine CAN Message


caution
  • 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.

OPERATION


4WD-ECU communicates with the engine-ECU via the CAN bus lines.

DIAGNOSIS CODE SET CONDITION


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

PROBABLE CAUSES



DIAGNOSIS 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 ).

STEP 2. M.U.T.-III diagnosis code.
Check the engine diagnosis code (Refer to GROUP 13A - Troubleshooting <4B1>, GROUP 13C -Troubleshooting <4J1>, GROUP 13D -Troubleshooting <4N1>).

Q. Is the diagnosis code set?
Perform the relevant troubleshooting.
Go to Step 3.

STEP 3. M.U.T.-III data list.
Check the following data list (Refer to ).

  • Item No.12: Engine speed

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 4.

STEP 4. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.U0401 set?
Replace the 4WD-ECU (Refer to ). Then go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.

Q. Is diagnosis code No.U0401 set?
Return to Step 1.
This diagnosis is complete.