Inspection Procedure 2: The ESS (emergency stop signal system) function does not work normally.


caution Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM


If the ESS (emergency stop signal system) function does not work normally, ETACS-ECU, ASC-ECU may be defective. Also, the ESS does not work when the hazard warning lamps illuminate.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the hazard warning lamps.
Check that the hazard warning lamps illuminate when the hazard warning lamp switch is turned ON.

Q. Is the check result normal?
Go to Step 2.
Refer to Inspection Procedure 1 "The hazard warning lamps do not illuminate" .

STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set in the ASC-ECU.

Q. Is the diagnosis code set?
Troubleshoot the ASC (Refer to GROUP 35C - Troubleshooting ).
Go to Step 3.

STEP 3. M.U.T.-III other system actuator test
ASC-ECU
  • Item 10: ESS test mode (Refer to GROUP 35C - Actuator test ).
OK: The ESS function operates.

Q. Is the check result normal?
Go to Step 4.
Replace the ASC-ECU (Refer to GROUP 35C - Hydraulic unit ).

STEP 4. Retest the system
Check that the ESS function works normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Go to Step 1.