The automatic day-night mirror uses two photocell sensors in order to determine light conditions in the front and the back of the vehicle. At night, as the glare of the headlamps from behind increases, the mirror gradually becomes darker in order to absorb the glare. In the daytime, the mirror is in a clear state. With the ignition switch in the ON position, battery positive voltage is applied to the automatic day/night mirror connector cavity. When the automatic day/night mirror switch is placed in the ON position, battery positive voltage is applied to the automatic day/night mirror circuit. Battery positive voltage is supplied at all times to the REVERSE Relay coil through the rear junction block. Battery positive voltage is supplied at all times to the REVERSE Relay switch through the NSBU Fuse through the rear junction block. The powertrain control module (PCM) sends a Class 2 message to the rear integration module (RIM) indicating that ignition switch is in the ON position and the gear selector lever is in the REVERSE position. When these conditions occur, the RIM pulls the REVERSE RELAY coil to ground. The coil is energized, closing the switch contacts. This supplies battery positive voltage to the automatic day/night mirror. The mirror will gradually change to a clear state as a result of the reverse input.

With the optional automatic outside mirror, the interior mirror also controls the reflectiveness of the left outside power mirror. The left outside power mirror darkens or clears along with the interior mirror.