Inspection Procedure 1: M.U.T.-III cannot communicate with WCM.


caution Before replacing the ECU, ensure that the communication circuit is normal.

COMMENTS ON TROUBLE SYMPTOM


WCM is communicating with M.U.T.-III via CAN. Therefore, communication error of WCM is suspected.

PROBABLE CAUSES



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 line (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 3.

STEP 2. Check the power supply circuit and the earth circuit to WCM.


Refer to Inspection Procedure 4 "Check WCM power supply/earth circuits" .

Q. Is the check result normal?

Go to Step 3.

Repair the power supply circuit and the earth circuit to WCM.

STEP 3. Retest the system


Check if M.U.T.-III can communicate with WCM.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace WCM and register the ID codes (Refer to ).