Principles Of Operation

Rear View Mirrors - Exterior

Principles of Operation

Adjusting the exterior mirror switch to the LH or RH position determines which exterior mirror motor will be controlled. The Driver Door Module (DDM) receives input from the exterior mirror control switch and controls the movement of the LH exterior mirror motor. The RH exterior mirror motor is controlled by the Driver Seat Module (DSM). When the exterior mirror control switch is activated for the LH mirror, the DDM receives an input signal and then applies voltage and ground to the LH exterior mirror motor to move the exterior mirror motor to the desired position. When the exterior mirror control switch is activated for the RH mirror, the DDM receives an input signal and then sends a Medium Speed Controller Area Network (MS-CAN) message to the DSM. The DSM will then apply voltage and ground to the RH exterior mirror motor to move the exterior mirror motor to the desired position.

The exterior mirrors use a jumper harness between the vehicle wire harness connector and the exterior mirror motor. The exterior mirror jumper harness is integral to the exterior mirror. Before replacing an exterior mirror or mirror motor, inspect the jumper harness for open and shorted circuits or damaged and pushed-out pins. If a concern with the exterior mirror jumper harness exists, attempt to repair the jumper harness.

Heated Exterior Mirror

The rear window defrost switch controls the operation of the heated exterior mirror glass. The heated exterior mirror glass only operates when the rear window defrost system is ON. The heated exterior mirror glass power is supplied by the rear window defrost relay through a separate Battery Junction Box (BJB) fuse that isolates the heated exterior mirror system from the rear window defrost system in the event of a concern.

LH Auto-Dimming Mirror

The LH exterior mirror is equipped with an auto-dimming feature. The interior auto-dimming rear view mirror controls the reflectance level of the LH exterior mirror to eliminate unwanted glare. The reflectance level of the mirror glass is variable and depends on the amount of rear glare in relation to ambient light conditions in front of the interior mirror. The auto-dimming feature is disabled when the vehicle is in REVERSE.

For information and diagnostics, refer to Rear View Mirrors - Interior Testing and Inspection.

Memory Exterior Mirrors

The memory mirror function recalls the preferred positioning of the exterior mirror motors when the transmission is in the PARK or NEUTRAL position and the door mounted switches or the Remote Keyless Entry (RKE) transmitter are activated.

Each exterior mirror motor is equipped with a potentiometer, which the DDM and DSM use to monitor the position of the mirrors. The DDM constantly tracks LH mirror motor position, while the DSM constantly tracks RH mirror motor position. When a mirror motor position is stored into memory by the operator, the respective module will retain this position for future recall. The position of the mirror motors are stored within memory as long as the module retains power. When a memory 1 or 2 switch is depressed on the memory SET switch, a ground input is sent to the DDM to recall the preferred seat, mirror and steering column position that is stored in memory. When the DDM receives an input signal from the memory SET switch, the DDM sends a MS-CAN message to the DSM. When a memory position is recalled by the operator, the DDM and DSM will power the exterior mirror motors simultaneously and monitor the potentiometer circuits. When the stored memory position is reached, the DDM and DSM will remove power from the exterior mirror motors. If the exterior mirror control switch is operated during a memory recall, the DDM and DSM will stop the memory recall and respond to the exterior mirror control switch command.

For information on the DDM, refer to Body Control Systems. For information on the DSM and Memory Position Programming, refer to Seats.

Puddle Lamps

The exterior mirrors are equipped with puddle lamps, which will illuminate when the interior lights are turned on by opening a door or by pressing the unlock button on the RKE.