On-Vehicle Inspection

WARNING: This page is about a different car, the 2006 Lexus GS 430 and 2006 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

CHECK AUTOMATIC LIGHT CONTROL SENSOR

Disconnect the L1 sensor connector.
Connect the voltmeter's positive (+) lead to terminal 6 and the negative (-) lead to terminal 3.

Measure the voltage of the connector.

Standard voltage

STANDARD VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition
L1-3 (CTLE) - L1-6 (CTLB)	Always	10 to 14 V

Fig 1: Identifying L1 Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance of the connector.

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
L1-3 (CTLE) - Body ground	Always	Below 1 Ω

Reconnect the L1 sensor connector.

Check the waveform of the L1 sensor connector.

STANDARD VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition	Tester Range
L1-3 (CTLE) - L1- 5 (CTLS)	Engine switch on (IG), Headlight dimmer switch in AUTO	Correct waveform is as shown	5 V/DIV., 5 msec./DIV.

HINT:

If the ambient light becomes brighter, width A becomes narrower.

If the result is not as specified, replace the automatic light control sensor.

Fig 2: Waveform L1 Sensor Connector