Inside Rearview Mirror with the Automatic Day-Night Feature System Operation

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

With the ignition switch in the ON position, ignition 1 voltage is supplied through the IGN 1 fuse in the left I/P fuse block to the inside rearview mirror. Ground for the inside rearview mirror is provided by G203.

The inside rearview mirror has 2 photocell sensors. The headlight sensor, located on the front of the mirror or mirror face. The headlight sensor is used to detect a high light condition such as headlights from a car behind. The ambient light sensor located on the back of the mirror or windshield side. The ambient light sensor is used to detect a low light or nighttime condition. In a low light or nighttime condition, with the automatic day-night feature enabled, the mirror will automatically darken the face to reduce the glare from the headlights. With the gear selector lever in the REVERSE position, backup lamp supply voltage is supplied as an input to the inside rearview mirror. This disables the automatic day-night feature of the mirror and allows the face to gradually change to a normal state. In the daytime, the mirror is in a normal state because of the high light condition that is detected by the ambient light sensor.

The inside rearview mirror will also darken the driver outside rearview mirror. The inside rearview mirror supplies a signal and a low reference to the driver outside rearview mirror.