Ambient Light Sensor

The ambient light sensor is supplied a reference ground from the Instrument Panel Integration Module (IPM) via CKT 61 (YEL). The sensor is a light sensitive variable resistor that resistance varies as the outside ambient light level changes. The IPM receives an input voltage proportional to the resistance of the resistor via CKT 278 (WHT). The IPM sends a Class 2 message to the Dash Integration Module (DIM) and the Rear Integration Module (RIM) indicating the daytime/nighttime status. The DIM uses the daytime/nighttime status of the ambient light sensor to automatically turn on and off the headlamps with the twilight sentinel on. The RIM uses the daytime/nighttime status of the ambient light sensor to automatically turn on and off the interior courtesy lamps with the interior lamp switch in the AUTO position.