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. Note that this function can be disabled/enabled by the adjustment 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

DIAGNOSTIC PROCEDURE

Step 1. Check that the headlamps operate.
Check that the low-beam and high-beam headlamps work normally.

Q. Is the check result normal?
Go to Step 2.
Repair the headlamps. Refer to trouble symptom chart .

Step 2. Pulse check
Check the input signals below, which are related to the headlamp automatic-shutdown function.
System switch
 Check condition
Ignition switch (IG1)
 When turned from ACC to ON
Driver’s door switch
 When the driver’s door is opened
Tail lamp switch
 When the lighting switch is turned to the TAIL position
OK: The M.U.T.-III sounds or the voltmeter needle fluctuates.

Q. Is the check result normal?
All the signals are received normally. : Go to Step 3.
The ignition switch (IG1) signal is not received. : Refer to Inspection Procedure P-2 "The ignition switch (IG1) signal is not received ."
The driver’s door switch signal is not received. : Refer to Inspection Procedure P-4 "The driver’s door switch signal is not received ."
The tail lamp switch signal is not received. : Refer to Inspection Procedure P-5 "The column switch (lighting and turn-signal lamp switch) signal is not received ."

Step 3. Customize function by using the SWS monitor
Check that the headlamp automatic-shutdown function has been enabled by using the customized function.
caution The SWS monitor must be used in order to confirm and change that setting. Use the SWS monitor to confirm and/or change the customized function.

Q. Is the check result normal?
Go to Step 4.
Enable the headlamp automatic-shutdown function by using the customized function (Refer to GROUP 54E, Customize function ).

Step 4. Retest the system.
Replace the ETACS-ECU, and then 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.