INSPECTION PROCEDURE K-5: 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.

  • Ignition switch (IG1)
  • Driver’s door switch
  • Tail lamp switch
  • Headlamp switch
If this function does not work normally, these input signal circuit(s), the front-ECU or the ETACS-ECU may be defective. On vehicles with keyless entry system, note that this function can be disabled/enabled by the customize function (default setting; enabled).

POSSIBLE CAUSES

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

DIAGNOSIS PROCEDURE

Step 1. Customize function by using the SWS monitor
Check that "H/L AUTO CUT" is set to "W.FUNCTION (A)" or "W.FUNCTION (D)" by using the SWS monitor customize function.

Q. Is the check result normal?
Go to Step 2.
Use the SWS monitor customize function to set "H/L AUTO CUT" to "W.FUNCTION (A)" or "W.FUNCTION (D)" (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.

  • Ignition switch: OFF
ECUS TO BE CHECKED
  • COLUMN ECU
  • ETACS ECU
  • FRONT ECU
OK: "OK" are displayed for all the items

Q. Are the check result normal?
"OK" are displayed for all the items : Go to Step 3.
"NG" is displayed on the "COLUMN ECU" menu. : Refer to Inspection Procedure A-2 "Communication with the column switch (column-ECU) is not possible ."
"NG" is displayed on the "ETACS ECU" menu. : Refer to Inspection Procedure A-3 "Communication with the ETACS-ECU is not possible ."
"NG" is displayed on the "FRONT ECU" menu. : Refer to Inspection Procedure A-4 "Communication with the front-ECU is not possible ."

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
  • Ignition switch: from ON to OFF
  • Lighting switch: "TAIL" or "HEAD"
Item No.
 Item name
 Normal condition
Item 00
 HEADLAMP SW
 ON when the lighting switch is at HEAD
Item 01
 TAIL LAMP SW
 ON when the lighting switch is at TAIL
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.

  • Driver’s door: open
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. Are the check result normal?
Normal conditions are displayed for all the items : Go to Step 4.
Normal condition is not displayed for item Nos.00 or 01. : Refer to inspection procedure P-5 "Column switch (lighting and turn-signal lamp switch) signal is not received ."
Normal condition is not displayed for item No.30. : Refer to inspection procedure P-2 "The ignition switch (IG1) signal is not received ."
Normal condition is not displayed for item No.32. : Refer to inspection procedure P-4 "The driver’s door switch signal is not received ."
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.

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 ETACS-ECU.