The outside rearview mirrors are controlled by the driver door switch assembly (DDSA) which contains the mirror control switches, the driver door module (DDM), and the passenger door module (PDM). The DDSA decodes mirror control switch activations while the door modules apply battery voltage and ground to their respective mirror motors to move the mirrors to the desired positions.

The outside rearview mirror adjustment switches are contained in the driver door switch assembly (DDSA). The Mirror Select Switch is used to select which mirror, driver or passenger, is to be adjusted. The Mirror Position Switch is used to move the mirror that has been selected for adjustment to the desired position. The DDSA reports the activity of these switches to the driver door module (DDM) and the passenger door module (PDM) via class 2 serial data circuit.

On vehicles that have the memory mirrors feature, the DDSA is also wired to, and receives direct signal inputs from the memory function switch. For more information concerning the memory function switch refer to Memory Seats Description and Operation in Seats.

Each mirror has 2 reversible motors for position adjustment; the vertical motor and the horizontal motor. Each reversible motor is wired to its associated door module through 2 motor control circuits. The door modules control the reversible motors by applying battery voltage and ground to these 2 motor control circuits. The door module reverses the polarity of the voltage and ground it applies to these 2 circuits in order to run the motor in opposite directions. For example, to run the mirror in the Up direction, the door module applies voltage to the mirror motor up control circuit, and ground to the mirror motor down control circuit. To run the mirror in the opposite Down direction, the module reverses the polarity, supplying voltage to the down control circuit, and ground to the up control circuit.

The memory mirrors are controlled by the mirror position sensors, the driver door switch assembly (DDSA), the driver door module (DDM), and passenger door module (PDM). The DDSA decodes memory switch activations while the mirror position sensors provide mirror position information to the door modules. The door modules supply voltage and ground to the mirror position sensors, store mirror position information, and apply voltage and ground to the mirror motors.

For memory operations, each outside rearview mirror has four additional circuits and contains a vertical position sensor and a horizontal position sensor. The position sensors, which are potentiometer type sensors, are attached to the corresponding position motor of each mirror, and provide constant information, in the form of feedback voltage to the associated door module to indicate the vertical and horizontal position of the mirror. Each position sensor of each mirror is wired to the corresponding front door module through four circuits to provide mirror location information in the following manner. Each door module supplies a 5-volt reference voltage and ground to both of its position sensors. Each door module also supplies 5 volts to the vertical position sensor signal circuit, and 5 volts to the horizontal position sensor signal circuit of the corresponding position sensor. When the mirror motors run, the resistance of the attached sensors vary, which in turn, varies the feedback voltage to the door module.

When mirror positions are programmed into the personalization package, the front door modules store the positions indicated by the feedback voltages of the position sensors. When a memory recall is requested, the door modules compare the feedback voltages indicated by the current mirror positions to the stored feedback voltages. The door modules then move the mirrors until the current feedback voltages match the stored feedback voltage levels.

The outside rearview mirrors heat during the defrost/defog cycles for the rear window. The driver door module (DDM) and passenger door module (PDM) control the heated mirror functions. The DDM supplies power and ground to the driver heated mirror and the PDM supplies it to the passenger heated mirror. When the door modules receive a class 2 serial data message from the HVAC control module indicating the rear defogger has been turned ON, both door modules will activate the heated mirror by applying voltage to the heated mirror element feed circuit.

The automatic day/night feature of the driver outside rearview mirror is controlled by the inside rearview mirror. The inside rearview mirror supplies a signal and a low reference to the driver outside rearview mirror. The voltage on the signal circuit of the driver outside rearview mirror varies between 0.5-1.5 volts depending on light conditions present at the inside rearview mirror. At night, with the automatic day-night feature enabled, the driver outside rearview mirror will automatically darken with the inside rearview mirror to reduce the glare from the headlamps from behind. The voltage on the signal circuit of the driver outside rearview mirror will be near 1.5 volts. In daytime conditions, the mirrors are in the normal state. The voltage on the signal circuit of the driver outside rearview mirror may be less than or near 0.5 volts. Refer to Automatic Day-Night Mirror Description and Operation in Stationary Windows for further description and operation of the inside rearview mirror.