Principles of Operation

Rear View Mirrors - Interior

Principles of Operation

Interior Auto-Dimming Rear View Mirror

The interior auto-dimming rear view mirror automatically reduces the glare caused by headlamps reflecting in the interior rear view mirror. Voltage is supplied to the interior auto-dimming mirror when the ignition is in RUN or ACC. The auto-dimming feature is disabled when the vehicle is in REVERSE.

The interior auto-dimming rear view mirror has 2 photoelectric sensors, forward facing and rearward facing sensors, that detect forward and rearward light conditions. Based on these inputs, the automatic dimming feature adjusts the reflectance level of the interior rear view mirror glass to eliminate unwanted glare. The reflectance level of the mirror glass is variable and depends on the amount of rear glare in relation to ambient light conditions in front of the interior mirror.

When the forward facing sensor detects daytime conditions, the rearward facing sensor is inactive and the mirror stays in a high reflectance mode. When the forward facing sensor detects nighttime conditions, the rearward facing sensor is active and detects glare from the headlights of vehicles approaching from the rear, or other glare producing light sources. To provide increased visibility when backing up, the interior rear view and LH exterior mirror automatically returns to a high reflectance mode whenever the vehicle is in REVERSE.

If the forward or rearward sensors are blocked, the automatic dimming interior mirror might not work correctly.