Inspection Procedure 6: The Headlamp Automatic-shutdown Function does not Work Normally.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.


COMMENTS ON TROUBLE SYMPTOM


The ETACS-ECU operates this function in accordance with the input signals below.

If this function does not work normally, these input signal circuit(s), the front-ECU or the ETACS-ECU may be defective. Note that this function can be disabled/enabled by the adjustment function (default setting; enabled).

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Customize function by using the SWS monitor.


Check that "Headlamp auto-cut" is set to "Spec.B(EU/EXP)" by using the adjustment function.

Q. Is the check result normal?

Go to Step 2.

Set "Headlamp auto-cut" is set to "Spec.B(EU/EXP)" by using the adjustment function. (Refer to ).

STEP 2. ECU check by using the SWS monitor.


Check that the power supply and earth lines to the column switch (column-ECU), the ETACS-ECU and the front-ECU and the SWS communication lines are normal.

ECUS TO BE CHECKED
OK: "OK" are displayed for all the items

Q. Is the check result normal?

YES ("OK" are displayed for all the items) : Go to Step 3.

NO ("NG" is displayed on the "COLUMN ECU" menu) : Refer to GROUP 54C - Trouble Symptom Chart .

NO ("NG" is displayed on the "ETACS ECU" menu) : Refer to GROUP 54C - Trouble Symptom Chart .

NO ("NG" is displayed on the "FRONT ECU" menu) : Refer to GROUP 54C - Trouble Symptom Chart .

STEP 3. SWS monitor data list.


Check the SWS communication signal, which are related to the headlamp automatic-shutdown function.
<Selected item> LIGHTING - HD AUTO-CUT
Item No.
 Item name
 Normal condition
Item 00
 HEADLAMP SW
 ON when the lighting switch is at HEAD
Item 30
 IG SW(IG1)
 from ON to OFF
Item 70
 FRONT ECU ACK
 SLEEP ACK or NORMAL ACK
Check that the M.U.T.-III displays normal condition when the condition above is changed to the condition below.

Item No.
 Item name
 Normal condition
Item 32
 DR DOOR SW
 ON
Item 35
 HD AUTO-CUT
 OFF
OK: Normal conditions are displayed for all the items

Q. Is the check result normal?

YES (Normal conditions are displayed for all the items) : Go to Step 4.

NO (Normal condition is not displayed for item No.00) : Refer to ETACS - Input Signal Chart .

NO (Normal condition is not displayed for item No.30) : Refer to ETACS - Input Signal Chart .

NO (Normal condition is not displayed for item No.32) : Refer to ETACS - Input Signal Chart .

NO (Normal condition is not displayed for item Nos.35 or 70) : Replace the front-ECU.

STEP 4. Retest the system.


Check that the headlamp automatic-shutdown function works normally.
(1)Replace the ETACS-ECU.
(2)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 Cope with Intermittent Malfunction ).

Replace the front-ECU.