Inspection Procedure 8: The Auto Lamp 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.

OPERATION


The ETACS-ECU operates this function in accordance with the input signals from driving distance, photo sensor, and auto lamp switch.

COMMENTS ON TROUBLE SYMPTOM


If the auto lamp function does not work normally, the above input signal circuit(s) or the ETACS-ECU may have a problem.

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 ).

STEP 2. M.U.T.-III diagnosis code


Check if diagnosis code is set to the ETACS-ECU.

Q. Is the diagnosis code set?

Troubleshoot the ETACS-ECU. Refer to .

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code


Check if diagnosis code is set to the combination meter.

Q. Is the diagnosis code set?

Troubleshoot the combination meter. Refer to .

Go to Step 4.

STEP 4. Check that the headlamps operate.


Check that the headlamps illuminate normally.

Q. Is the check result normal?

Go to Step 5.

Refer to Inspection Procedure 1 "The low-beam headlamps do not illuminate normally." .

STEP 5. M.U.T.-III data list


Use the ETACS-ECU service data to check the signals related to the operation of auto lamp function.

Item No.
 Item name
 Normal condition
Item 254
 IG voltage
 Battery voltage
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 6.

Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 2 "The ignition switch (IG1) signal is not received" .

STEP 6. Retest the system


Check that the auto lamp 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.