Inside Rearview Mirror with the Automatic Day-Night Feature System Components
The inside rearview mirror with the automatic day-night feature system consists
 of the following components:
|     •  | Driver outside mirror with the automatic day-night feature | 
 
Inside Rearview Mirror with the Automatic Day-Night Feature Switches
The inside rearview mirror has 5 switches that perform the following functions:
|     •  | The HomeLink transmitter switches | 
 
|     •  | The automatic day-night mirror switch | 
 
Power and Ground of the Inside Rearview Mirror
|     •  | With the ignition ON, ignition voltage is supplied to the mirror from
 the IGN E fuse in the underhood fuse block. | 
 
|     •  | Ground for the mirror is provided by G301. | 
 
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 rear side of the mirror. The other sensor
 is the ambient light sensor, located on the front of the mirror or windshield
side. With the 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.
 In the daytime, the mirror is in a normal state because of the high light
 condition that is indicated by the ambient light sensor. With the gear selector
 lever in the REVERSE position, backup lamp supply voltage is supplied as an input
 to the inside rearview mirror. In night time conditions only, 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 clearly see objects
 in the mirror when backing up. The mirror also disables the automatic day-night
feature when when either door is opened and the courtesy lights are illuminated.
Driver Outside Rearview Mirror with the Automatic Day-Night Feature Operation
The drivers outside rearview mirror will also darken when the inside rearview
 mirror darkens. The inside rearview mirror supplies a low reference circuit and
a control circuit to the drivers outside rearview mirror.