The power outside rearview mirror system consists of the following components:

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

In order to control power outside rearview mirror operations, as well as other front door functions, the front door modules must be powered up. For this purpose, battery voltage is supplied by the rear fuse block, through separate circuits, to each front door module. Each front door module is separately grounded through a ground stake. These voltage and ground supplies, however, are also used by the front door modules to power the outside rear view mirror switches and motors. And, in addition, the voltage and ground supplies are used to provide power and ground to the associated window and lock switches, door lock actuators, and window express up sensors.

Front door modules battery voltage is supplied as follows:

These circuits are in the C3 harness connector of each door module and must not be confused with the battery voltage and ground circuits that are used exclusively to drive the power window motors. For more information concerning the window motor power and ground circuits, refer to Power Windows Description and Operation

For outside rearview mirror adjustments, the driver door switch assembly (DDSA) contains two built-in switches, the Mirror Select Switch, and the Mirror Position Switch. The Mirror Select Switch is used to select which mirror, left or right, 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 two built-in switches to the driver door module (DDM) and the front passenger door module (PDM), via the class 2 serial data circuit.

The Mirror Select Switch contacts, which are normally open, receive voltage and ground from the DDSA. When, either the left or right mirror has been selected for adjustment, the contacts indicating that selection are closed to ground and the voltage is pulled low. The DDSA processes this voltage information to determine which mirror will be adjusted. One of the mirrors must be selected before the mirror can actually be adjusted.

The Mirror Position Switch has four sets of contacts, one set in each corner of the switch. The DDSA supplies voltage to one side of each set of contacts, and ground to the other side of each set of contacts. The Mirror Position Switch contacts are designated as Left-Up, Left-Down, Right-Up, and Right-Down. When the switch is operated in a Left-Up, Left-Down, Right-Up, or Right-Down direction, the contacts for that direction are closed to ground, voltage flows through the circuit, and the DDSA recognizes this as a command to move the mirror in the corresponding direction. When the switch is operated in a direct Up, Down, Left, or Right direction, the switch simultaneously closes two sets of contacts, voltage flows through both sets, and the DDSA recognizes this two contact signal as a one direction command to move the mirror in the direction common to the two signals. For example, if the switch is operated to a direct Up position, both the Left-Up and Right-Up contacts are closed. The direction common to the two sets of contacts is Up and the mirror will move in that direction. For all Mirror Position Switch operations, the DDSA sends the appropriate mirror request to the appropriate front door module via the class 2 serial data circuit.

On vehicles that have the A45 memory mirrors feature, the DDSA is also wired to, and receives direct signal inputs from, the memory function switch.

Each mirror has two reversible mirror motors for position adjustment. These are the vertical motor and the horizontal motor. Each mirror motor is wired to its associated door module through two motor control circuits. The door modules control the reversible motors by applying battery voltage and ground to the appropriate motor control circuits. The door module reverses the polarity of the voltage and ground it applies to the motor control circuits in order to move the motor in an opposite direction.

When the mirror is being operated in a direction that closes only one set of the mirror position switch contacts, i.e. Left-Up, Left-Down, Right-Up, or Right-Down, the associated door module applies voltage and ground to the appropriate circuits of both the vertical motor, and the horizontal motor to move the mirror in the two corresponding directions.

When the mirror is being operated in a direction that closes two sets of the mirror position switch contacts, i.e. Up, Down, Left, or Right, the door module applies voltage and ground to only that motor which controls movements in the direction common to both contacts. For example, if the mirror is being operated to a direct Up position, both the Left-Up and the Right-Up switch contacts are closed. The direction common to the contacts is the Up direction. Since the DDSA interprets that as a one direction command, the associated door module applies battery voltage and ground only to the vertical mirror motor to move the mirror UP.

Front door modules cannot perform memory mirror functions unless the Personalization Option is activated. The Dash Integration Module (DIM) stores the vehicles Personalization Option setting provided at the assembly plant. The DIM reports this Personalization Option setting to both front door modules, as well as other receiving modules, each time the ignition switch is cycled to RUN. The front door modules then store the Personalization Option setting and examine it before making a memory mirrors adjustment.

The Personalization Option setting stored within the front door modules will not change until the Personalization Option setting within the DIM is changed and the ignition switch then cycled to RUN.

If the Personalization Option is activated on a vehicle that is not equipped with A45, the door modules will erroneously set DTCs B1586 and B1591.

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

For memory mirror operations, each outside rearview mirror has four additional circuits and contains a vertical position sensor and a horizontal position sensor. The position sensors are attached to the corresponding position motor and are an integral part of each mirror. The position sensors, which are potentiometer type sensors, provide constant information, in the form of feedback voltage, to the associated door module, indicating the vertical and horizontal position of the mirror. Each front door module supplies 5 volts reference voltage, through a 5 volt reference circuit, and ground through a mirror sensor low reference circuit, to the position sensors. Each front door module also supplies 5 volts through the vertical position sensor signal circuit, and, 5 volts through the horizontal position sensor signal circuit, to 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. Feedback voltage for each sensor varies between 0.25 volts and 4.75 volts

When the mirror positions are programmed into the personalization package, the front door modules store the mirror 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 voltages.

If the vehicle is equipped with memory mirrors, it is equipped with the parallel parking mode feature. For this feature, the front passenger door module (PDM) communicates with the powertrain control module (PCM) over the class 2 serial data circuit. When the gear selector is shifted to reverse, the PCM transmits this status via a class 2 message to the PDM. The PDM then supplies battery voltage and ground of the correct polarity to the vertical motor of the RH outside rear view mirror to tilt the mirror down 7 degrees. This allows the driver to see the curb while parallel parking.

The mirrors heat during the defrost/defog cycles for the rear window. The heated mirrors are wired to the driver door module (DDM) and the front passenger door module (PDM) respectively. The DDM and the PDM receive a class 2 message from the instrument panel cluster (IPC) via the rear integration module (RIM) commanding the heated mirrors ON. The DDM and PDM first examine information from the dash integration module (DIM) to determine if vehicle conditions are correct for the heated mirrors function to be permitted. If conditions are correct, the DDM then applies battery voltage and ground to the driver side mirror heater element, and the PDM applies battery voltage and ground to the passenger side mirror heater element.

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 to 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 the daytime, the mirrors are in a 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.

Export vehicles may also have the power folding mirrors feature. This feature allows the operator to simultaneously retract both mirrors to a fully folded position in which they are closely tucked in and parallel to, the front door windows, or to extend them to the fully unfolded position for normal everyday use.

For this feature, the driver door switch assembly (DDSA) has an additional power folding mirrors switch built into it and, each mirror contains an additional power folding mirror motor. When the switch is activated to fold the mirrors, the normally open switch contacts close, the DDSA interprets the signal input and sends the command on to the driver door module (DDM) and the front passenger door module (PDM). The DDM and the PDM then each apply battery voltage and ground to the appropriate circuits of their respective power folding motors in order to retract both mirrors. When the switch is activated to unfold the mirrors, the door modules reverse the polarity of the voltage and ground applied to the reversible folding motors in order to move both mirrors to the fully extended position.

The power folding mirrors switch is activated by momentarily pressing the switch button. Each subsequent press will activate the mirrors to the opposite function of the preceding press, i.e. if the mirrors are currently folded, the next press of the switch will cause them to unfold and vice-versa.