On-Vehicle Inspection

WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

Disconnect the Q3 automatic light control sensor connector.

Measure the voltage and resistance according to the value(s) in the table below.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
Q3-6 (CLTB) - Q3-3 (CLTE)	Engine switch off	Below 1 V
Q3-6 (CLTB) - Q3-3 (CLTE)	Engine switch on (IG)	10 to 14 V

Fig 1: Identifying Q3 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
Q3-3 (CLTE) - Body ground	Below 1 Ω

If the result is not as specified, there is malfunction on the wire harness side.

Reconnect the automatic light control sensor connector.
Connect an oscilloscope to the automatic light control sensor connector.

Check the waveform.

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Tool Setting	Condition	Specified Condition
Q3-3 (CLTE) - Q3-5 (CLTS)	5 V/DIV., 5 ms./ DIV	Engine switch on (IG), light control switch in AUTO	Correct waveform is as shown

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: Identifying Signal Waveform