Automatic Day/Night Mirror - Operation

OPERATION

Both the inside and outside automatic dimming mirrors receive battery current through a fused ignition switch output (run/start) circuit and fuse in the Totally Integrated Power Module (TIPM), and will only operate when the ignition switch is in the ON or START positions.

INSIDE

The lighted switch on the automatic dimming inside rear view mirror provides the vehicle operator with a manual control of whether the automatic dimming feature is operational. When AUTO is selected, the mirror switch is illuminated. However, if the mirror is turned OFF manually, the mirror switch illumination is extinguished. However, the mirror will always turn back ON by default at the onset of a new ignition ON cycle. The automatic dimming mirror circuitry also senses the backup lamp circuit, and will automatically disable its self-dimming feature whenever the transmission gear selector is in the REVERSE position.

The ambient photocell sensor of the mirror faces forward, to detect the outside light levels through the windshield glass. A second headlamp photocell sensor is located in the upper right quadrant of the mirror face, to detect the light level received at the rear window side of the mirror. When the mirror control circuitry detects that the difference between the two sensed light levels has become too great (the light level received at the rear of the mirror is much higher than that at the front of the mirror) the mirror begins to darken. A thin layer of electrochromic material between two pieces of conductive glass make up the face of the mirror.

On vehicles equipped with an optional driver side automatic dimming outside rear view mirror, the signal to control the dimming of that mirror is generated by the automatic dimming inside rear view mirror circuitry. That signal is then delivered to the driver side outside rear view mirror on two hard wired circuits.

OUTSIDE

The driver side automatic dimming outside mirror is operated by the same controls and circuitry as the automatic inside rear view mirror. When the automatic inside rear view mirror is switched ON or OFF, the automatic dimming outside mirror is likewise switched ON or OFF. Just as in the automatic inside rear view mirror, a thin layer of electrochromic material between two pieces of conductive glass make up the face of the automatic dimming outside mirror. However, the signal to control the dimming of the outside mirror is generated by the automatic dimming inside rear view mirror control circuitry based upon the inputs from the two photocell sensors integral to the inside mirror. That signal is then delivered to the driver side outside rear view mirror on two hard wired circuits.