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.


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



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 to the ABS-ECU or ASC-ECU.

Q. Is the diagnosis code set to the any of the above?

Set to the ABS-ECU. : Troubleshoot the ABS. Refer to GROUP 35B - Troubleshooting .
Set to the ASC-ECU. : Troubleshoot the ASC. Refer to GROUP 35C - Troubleshooting .
The diagnosis code is not set. : Go to Step 3

STEP 3. M.U.T.-III other system actuator test

  • Item 10: ESS test mode (Refer to <ABS> or <ASC>).
OK: The ESS function operates.

Q. Is the check result normal?

Go to Step 4
Replace the ABS-ECU or ASC-ECU.

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