GM Service Manual Online
For 1990-2009 cars only

Outside Mirror Description and Operation Heated Mirrors

Heated Mirror System

Heated Mirror System Components

The heated mirror system consists of the following components:

    • HVAC control module
    • DEFROST relay
    • DEFG 10A fuse
    • Left outside power mirror
    • Right outside power mirror

Heated Mirror System Controls

The heated mirror system is activated by depressing the rear window defogger switch, which is part of the HVAC control module. For further information on the rear window defogger operation, refer to Rear Window Defogger Description and Operation .

Heated Mirror System Operation

The heated mirror system operates in parallel to the rear window defogger. Each outside rearview mirror contains a heating element that is connected to a constant ground source. When the rear window defogger system is active, battery voltage is available to the outside rearview mirrors through the heated mirror supply voltage circuit. The mirrors will heat up to remove ice, snow or frost and will automatically deactivate when the rear defogger system has timed out, approximately 10 minutes.

Outside Mirror Description and Operation Power Mirrors

Power Mirror System Components

The power mirror system consists of the following components:

    • Power mirror switch
    • Selector switch
    • Left outside power mirror
    • Right outside power mirror
    • DDM 10A fuse

Each of the outside power mirrors contains 2 reversible motors. The vertical motor operates the up and down directions and the horizontal motor operates the left and right directions. Each of the power mirror motors are circuit breaker protected.

Power Mirror System Controls

The power mirror switch incorporates a mirror selector switch and a 4-position mirror direction switch.

The mirror select switch allows the operator to select the mirror to be moved by rotating counterclockwise to the L position (left outside power mirror) or rotating clockwise to the R position (right outside power mirror).

The mirror direction switch is a four position switch that allows the operator to move the selected mirror up, down, left or right.

Power Mirror System Operation

The power mirror switch receives power through the battery supply voltage circuit and the DDM fuse. The power mirror switch also receives a constant ground.

The 4 positions of the direction switch have dual switch contacts. Each of the contacts are connected to opposing sides of the appropriate power mirror motors through the selector switch. The selector switch interrupts or completes these circuits depending on the position of the selector switch (L or R).

If the selector switch is placed in the L position and the up switch is depressed, battery voltage will be supplied to the left outside power mirror vertical motor through the left mirror motor up direction circuit and return to the power mirror switch through the mirror motor common circuit then to ground and the mirror will move up. If the down switch is depressed, the common circuit supplies battery voltage and the left mirror motor up direction circuit completes the path to the power mirror switch then to ground and the mirror will move down.

The remainder of the mirror functions operate in the same manner as described above. The thing to remember is, that by placing the power mirror switch in opposing positions (left/right or up/down) will reverse the polarity of the mirror motor, utilizing the same circuits and the power mirror will move accordingly.