Principles of Operation

Rear View Mirrors - Exterior

Principles of Operation

The movement of the LH and RH exterior mirror glass is controlled by the exterior mirror control switch and the LH and RH exterior mirror motors. Adjusting the exterior mirror switch to the LH or RH position determines which exterior mirror motor will be controlled. The exterior mirror control switch logic is the selected movement request from the exterior mirror control switch. When the exterior mirror control switch is adjusted to the left, right, up or down position, the exterior mirror control switch will supply voltage and ground to the selected exterior mirror motor to move the exterior mirror glass to the desired position.

Only vehicles equipped with memory exterior rear view mirrors are capable of setting DTCs.

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. If a concern with the exterior mirror jumper harness exists and cannot be repaired, a new exterior mirror must be installed.

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 Smart Junction Box (SJB) fuse 9 (10A), which isolates the heated exterior mirror system from the rear window defrost system in the event of a concern. The heated exterior mirrors should be warm to the touch after 4 minutes of operation.

LH Auto-Dimming Mirror

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. To provide increased visibility when backing up, the interior rear view mirror glass and LH exterior mirror glass will automatically return to a high reflectance mode whenever the gear selector is in REVERSE.

For information and diagnostics, refer to Rear View Mirrors - Interior Special Tool(s) Used With Diagnostics.

Memory Exterior Mirror

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

Each exterior mirror motor is equipped with a potentiometer, which the Driver Door Module (DDM) and Driver Seat Module (DSM) use to monitor the position of the mirrors. The DDM constantly tracks LH mirror motor position. The DSM constantly tracks RH mirror motor position. When a mirror motor position is stored in memory by the operator, the module will retain this position in memory for future recall. The position of the mirror motors are stored within the DDM and DSM memory as long as the modules retain power. 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 Handles, Locks, Latches and Entry Systems Testing and Inspection.

For information on the DSM and Memory Position Programming, refer to Seating Programming and Relearning.

Puddle Lamps

The exterior mirrors may be 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 remote transmitter, if equipped. For information on the mirror-mounted puddle lamps, refer to Exterior Lighting Testing and Inspection.