GM Service Manual Online
For 1990-2009 cars only

Power Mirror System Components

The power mirror system consists of the following components:

    • Outside rearview mirror switch
    • Mirror selector switch
    • Driver outside rearview mirror
    • Passenger outside rearview mirror
    • PWR MIRROR Fuse 10A
    • Memory seat module, w/A43

Each of the outside power mirrors contains two 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 outside rearview mirror switch is a four position directional switch (Up, Down, Left and Right).

The mirror select switch is a three position switch (L, Off and R).

The memory seat module controls mirror operation on vehicles with the A43 memory seat and mirrors option.

Power Mirror System Operation w/o A43

The outside rearview mirror switch receives power through the battery positive voltage circuit from the PWR MIRROR 10A Fuse. The power mirror switch also receives a constant ground.

The four 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 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 positive voltage will be supplied to the left outside rearview mirror vertical motor through the left mirror motor up control circuit and ground through the left mirror motor left control circuit. If the down switch is depressed, battery positive voltage will be supplied to the left outside rearview mirror vertical motor through the left mirror motor left control circuit and ground through the left mirror motor up control circuit.

The remainder of the mirror functions operate in the same manner as described above. Placing the power mirror switch in opposing positions (left/right or up/down) will reverse the polarity to the mirror motor.

Power Mirror System Operation w/A43

The outside rear view mirror switch supplies power and ground inputs to the memory seat module (MSM) for use in driving the driver and passenger outside rearview mirror horizontal and vertical motors. When the MSM recognizes the input combination, it moves the appropriate mirror motor in the requested direction.

The MSM receives inputs from the mirror position sensors during Memory 1 and Memory 2 recall. The potentiometers in the position sensors vary in resistance as the motors move the mirror. The MSM receives a variable voltage input depending on the resistance of the potentiometer. During memory set, the MSM records the voltages across the mirrors. During memory recall, the MSM moves the mirror motors until the voltage across each potentiometer matches the recorded voltage.

Parallel Park Assist Mirror Operation

When the vehicle is shifted into reverse, the passenger outside rearview mirror will tilt down five degrees or to the end of travel. The passenger outside rearview mirror will return to its original position 5 seconds after the the vehicle is shifted out of reverse.