INSPECTION PROCEDURE K-1: The headlamps do not illuminate when the lighting switch is at "TAIL" or "PASSING" position, but illuminate only at low beam when the switch is at "HEAD" position. However, the headlamps do not illuminate at high beam.

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

If the headlamps illuminate only at low beam regardless of the lighting switch position, the headlamp fail-safe function may be activated.

POSSIBLE CAUSES

Malfunction of the column switch

Malfunction of the front-ECU

Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. ECU check on 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.

Ignition switch: OFF

ECUS TO BE CHECKED

COLUMN 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 2

.
"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 "FRONT ECU" menu.: Refer to Inspection Procedure A-4 "Communication with the front-ECU is not possible"

Step 2. Retest the system.

Check that the headlamps illuminate normally.

Q: Is the check result normal?

YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

).
NO: Replace the column switch.



INSPECTION PROCEDURE K-1: The headlamps do not illuminate when the lighting switch is at "TAIL" or "PASSING" position, but illuminate only at low beam when the switch is at "HEAD" position. However, the headlamps do not illuminate at high beam.

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

	COMMENTS ON TROUBLE SYMPTOM If the headlamps illuminate only at low beam regardless of the lighting switch position, the headlamp fail-safe function may be activated.
	POSSIBLE CAUSES Malfunction of the column switch Malfunction of the front-ECU Damaged harness wires and connectors
	DIAGNOSIS PROCEDURE

	Step 1. ECU check on 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. Ignition switch: OFF ECUS TO BE CHECKED COLUMN 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 2 . "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 "FRONT ECU" menu.: Refer to Inspection Procedure A-4 "Communication with the front-ECU is not possible" .
	Step 2. Retest the system. Check that the headlamps illuminate normally. Q: Is the check result normal? YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Replace the column switch.