Automatic Day-Night Mirror Description and Operation

AUTOMATIC DAY-NIGHT MIRROR DESCRIPTION AND OPERATION

INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE SYSTEM COMPONENTS
The inside rearview mirror with the automatic day-night feature system consist of the Inside rearview mirror.

POWER AND GROUND OF THE INSIDE REARVIEW MIRROR
- With the ignition ON, ignition voltage is supplied to the mirror from the HVAC/IP IGN 10-amp fuse in the body control module (BCM).
- Ground for the mirror is provided by G401.

INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE SYSTEM OPERATION
The inside rearview mirror uses 2 photocell sensors. One sensor is the headlight sensor, located on the face side of the mirror. The headlight sensor is used to determine light conditions present at the mirror face. The other sensor is the ambient light sensor, located on the front of the mirror or windshield side. The ambient light sensor is used to determine light conditions present at the mirror. With automatic day-night feature enabled, the mirror uses the ambient light sensor to determine the exterior light condition. With a low light condition detected, and a high light condition from behind at the headlight sensor, the inside rearview mirror will automatically darken the face of the mirror.

With the gear selector lever in the REVERSE position, backup lamp supply voltage is supplied as an input to the inside rearview mirror. The mirror monitors this input to disable the automatic day-night feature which allows the face to gradually change to a normal state. This allows the driver to see objects in the mirror clearly when backing up.

SWITCHES OF THE INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE AND ONSTAR(R)
The inside rearview mirror has 4 switches that perform the following functions:
- The on/off switch located at the left side of the mirror turns the automatic day-night feature on/off.
- The 3 switches on the right side of the mirror are for OnStar(R) operation. For more information, refer to OnStar Description and Operation.