On-Vehicle Inspection

WARNING: This page is about a different car, the 2012 Lexus LS 460. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

Fig 1: Identifying M2 Automatic Light Control Sensor Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connect the voltmeter's positive (+) lead to terminal M2-6 and the negative (-) lead to terminal M2-3.

Measure the voltage of the connector.

Standard voltage

Tester Connection	Switch Condition	Specified Condition
M2-6 (CLTB) - M2-3 (CLTE)	Engine switch on (IG)	11 to 14 V

Measure the resistance of the connector.

Standard resistance

Tester Connection	Condition	Specified Condition
M2-3 (CLTE) - Body ground	Always	Below 1 Ω

Check the waveform of the M2 sensor connector.

Fig 2: Identifying Signal Waveform

Wave form

Tester Connection	Switch Condition	Specified Condition	Tester Range
M2-3 (CLTE) - M2-5 (CLTS)	Engine switch on (IG), Headlight dimmer switch on 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.