INSPECTION PROCEDURE 1: Communication Between M.U.T.-III and Transfer-ECU Cannot Be Established


caution
  • If there is any problem in the CAN bus lines, an incorrect trouble symptom may occur. Prior to this diagnosis, always diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

SYMPTOMS



PROBABLE CAUSES



  • Wrong M.U.T.-III wiring harness
  • The CAN bus line is defective.
  • Transfer-ECU power supply circuit malfunction
  • Malfunction of transfer-ECU
  • ECU malfunction of other system

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?
Check/repair the transfer-ECU power supply circuit. (Refer to .)
Repair the CAN bus lines. (Refer to GROUP 54D - Troubleshooting ).