Inspection Procedure G-6: 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, ABS-ECU or TCL/ASC-ECU may be defective. Also, the ESS does not work when the hazard warning lamps illuminate.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the 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 2.

STEP 2. 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 3.
Refer to Inspection Procedure G-5 "The hazard warning lamps do not illuminate" .

STEP 3. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the ABS-ECU or TCL/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 TCL/ASC-ECU. : Troubleshoot the TCL/ASC. Refer to GROUP 35C - Troubleshooting .
The diagnosis code is not set. : Go to Step 4.

STEP 4. M.U.T.-III other system actuator test
ABS-ECU or TCL/ASC-ECU
  • Item 10: ESS test mode (Refer to <ABS> or <TCL/ASC>).
OK: The ESS function operates.

Q. Is the check result normal?
Go to Step 5.
Replace the ABS-ECU or TCL/ASC-ECU.

STEP 5. 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 ).
Replace the ETACS-ECU.