Inspection Procedure 7: The headlamp automatic shutdown function does not work normally.

caution

Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

OPERATION

The ETACS-ECU operates this function in accordance with the input signals from column switch (lighting switch), ignition switch (IG1), and driver’s door switch.

COMMENTS ON TROUBLE SYMPTOM

If the headlamp automatic shutdown function does not work normally, the above described input circuits or ETACS-ECU may have a problem. Also, it may be possible that the headlamp automatic shutdown function is set to "Disable" through customisation.

PROBABLE CAUSES

Malfunction of driver’s door switch
Malfunction of the ETACS-ECU
Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Customise function check

Use the ETACS-ECU customise function to check that the "Head lamp auto cut customize" is set to "Enable (B-spec.)"

Q. Is the check result normal?

Go to Step 2.

Use the ETACS-ECU customise function to set the "Head lamp auto cut customize" to "Enable (B-spec.)" (Refer to

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 data list

Use the ETACS-ECU service data to check the signals related to the operation of headlamp automatic shutdown function.

Turn the ignition switch to the LOCK (OFF) position.
Turn the lighting switch to the "TAIL" position.

Item No.	Item name	Normal condition
Item 254	IG voltage	1 V or less
Item 340	Head lamp switch (tail)	ON

Turn the lighting switch to the "HEAD" position.

Item No.	Item name	Normal condition
Item 341	Head lamp switch	ON

Open the driver’s door.

Item No.	Item name	Normal condition
Item 256	Dr door ajar switch	Open

OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?

Normal conditions are displayed for all the items.

: Go to Step 4.

Normal condition is not displayed for item No. 254. : Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 2 "The ignition switch (IG1) signal is not received"

.

Normal condition is not displayed for item No. 340 or 341. : Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 11 "The column switch signal is not received"

.

Normal condition is not displayed for item No. 256. : Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 5 "The front door switch (driver’s side) signal is not received"

STEP 4. Retest the system

Check that the headlamp automatic shutdown 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.