Inspection Procedure 2: The High-beam Headlamps do not Illuminate Normally.


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


COMMENTS ON TROUBLE SYMPTOM


If the high-beam headlamps do not illuminate, the dimmer switch input circuit or the front-ECU may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. ECU check by using the SWS monitor.


Check that the power supply and earth lines to the column switch (column-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 2.

NO ("NG" is displayed on the "COLUMN 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 2. Function diagnosis by using the SWS monitor.


Check the SWS communication signal, which are related to the high-beam headlamps.
<Selected item> LIGHTING - HEADLAMP HI
Item No.
 Item name
 Normal condition
Item 00
 HEADLAMP SW
 ON
Item 02
 DIMMER SW
 from OFF to ON, and then to OFF again ("ON" should be displayed when the dimmer switch is operated)
Item 03
 PASSING SW
 OFF
Item 30
 IG SW(IG1)
 ON
Item 35
 HD AUTO-CUT
 OFF
Item 70
 FRONT ECU ACK
 NORMAL ACK
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 3.

NO (Normal condition is not displayed for item Nos.00, 02 or 03) : 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.35) : Refer to Inspection Procedure 6 "The headlamp automatic-shutdown function does not work normally .

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

STEP 3. Retest the system.


Check that the high-beam headlamps illuminate 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.