On-Vehicle Inspection

WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR

Disconnect the K1 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

SPECIFIED CONDITION AND TESTER CONNECTION

Tester Connection	Condition	Specified Condition
K1-3 (CTLE) - K1-6 (CTLB)	Engine switch on (IG)	10 to 14 V

Measure the resistance of the connector.

Standard resistance

SPECIFIED CONDITION AND TESTER CONNECTION

Tester Connection	Condition	Specified Condition
K1-3 (CTLE) - Body ground	Always	Below 1 ohms

Fig 1: Identifying K1 Sensor Connector

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Reconnect the K1 sensor connector.

Check the waveform of the K1 sensor connector.

SPECIFIED CONDITION AND TESTER CONNECTION

Tester Connection	Condition	Specified Condition	Tester Range
K1-3 (CTLE) - K1-5 (CTLS)	Engine switch on (IG), Headlight dimmer switch in AUTO	Correct waveform is as shown	5 V/DIV., 5 msec./DIV.

Fig 2: Signal Waveform Graph (K1 Sensor)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

HINT:

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

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