INSPECTION PROCEDURE L-4: The high-beam and low-beam headlamps do not illuminate when the passing switch is operated.


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

COMMENTS ON TROUBLE SYMPTOM
If the low-beam and high-beam headlamps are normal, the passing switch input signal circuit or the front-ECU may be defective.

POSSIBLE CAUSES

  • Malfunction of the column switch
  • Malfunction of the front-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Check the operation of the headlamps.
Check that the low-beam and high-beam headlamps illuminate normally.

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

Step 2. SWS monitor data list.
Check the ETACS-ECU signals which are related to the headlamps.
<Selected item> COLUMN ECU
  • Passing lamp switch: ON
Item No.
 Item name
 Normal condition
Item 03
 PASSING SW
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?
Go to Step 3.
Refer to inspection procedure P-6 "The column switch (lighting and turn-signal lamp switch) signal is not received ."

Step 3. Retest the system.
When the passing switch is turned on, check if the 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.