Inspection Procedure 3: The FCM is cancelled in conjunction with a warning message while the FCM is activated.


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 (Refer to GROUP 54C - Troubleshooting ).
  • Before replacing the ECU, ensure that the communication circuit is normal.
  • When the FCM-ECU is replaced, calibrate the radar (refer to ).

COMMENTS ON TROUBLE SYMPTOM

  • The FCM-ECU has detected FCM control cancel signal.
  • The FCM is disabled under any of the conditions:

    1. Transfer position: 4LLc
    2. Rear differential lock: ON
    3. Hill descent control: ON
    4. ASC: OFF
    5. Noise is detected.
  • A malfunction may be present in the CAN bus line between the FCM-ECU and the ASTC-ECU or the ASTC-ECU itself.

PROBABLE CAUSES

  • Wiring harness or connector failure of CAN bus line
  • The ASTC system fails
  • Malfunction of FCM-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

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
Use M.U.T.-III to check that the diagnosis code is set by the FCM-ECU.

Q. Is the diagnosis code set?
Troubleshoot for the relevant diagnosis code (Refer to ).
Go to Step 3.

STEP 3. M.U.T.-III diagnosis code
Use M.U.T.-III to check that the diagnosis code is set by the ASTC-ECU.

Q. Is the diagnosis code set?
Carry out the diagnosis for the diagnosis code (Refer to ).
Go to Step 4.

STEP 4. Retest the system.
Check that the FCM control operates normally.

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).
Replace the FCM-ECU (Refer to ).