Automatic Light Control
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
The automatic light control sensor converts the intensity of the illumination into frequency and inputs it to the anti-theft ECU. When the light control switch is set at AUTO, the signal is input to TERMINAL A of the anti-theft ECU. Through communication control of the body ECU etc., the taillights and headlights are automatically turned on or off. See WIRING DIAGRAMS .
- Turn On Operation - When the anti-theft ECU receives the frequency signal from the automatic light control sensor and determines that the brightness around the vehicle has decreased below a specified level, terminal TAIL and HEAD of the anti-theft ECU are controlled through communication control of the body ECU etc. As a result, the taillights and/or headlights light up as the TAIL relay and/or HEAD LP relay are turned on. See WIRING DIAGRAMS .
- Turn Off Operation - When the anti-theft ECU receives the frequency signal from the automatic light control sensor and determines that the brightness around the vehicle has exceeded a specified level, terminal TAIL and HEAD of the anti-theft ECU are controlled through communication control of the body ECU etc. As a result, the taillights and/or headlights go off as the TAIL relay and/or HEAD LP relay are turned off. See WIRING DIAGRAMS .