Outside Rearview Mirror System Components
The power outside rearview mirror system consists of the following components:
| • | Driver door switch assembly (DDSA)--GMLAN device that contains the mirror select, fold and direction switches. |
| • | Driver door module (DDM)--GMLAN device that controls the mirror horizontal, vertical and fold motors. Supplies a 5-volt and low reference to the mirror position sensors, interprets and stores their positions. |
| • | Passenger front door module (PDM)--GMLAN device that controls the mirror horizontal, vertical and fold motors. Supplies a 5-volt and low reference to the mirror position sensors, interprets and stores their positions. |
| • | Remote control door lock receiver (RCDLR)--GMLAN device that provides driver identification information to the DDM and PDM for memory recalls. |
| • | Base or navigation radio--GMLAN device that provides driver identification setup and recall information to the DDM and PDM. |
| • | Driver outside mirror--Contains horizontal, vertical and fold mirror motors, heating elements, auto dimming and also horizontal and vertical position sensors if equipped. |
| • | Passenger outside mirror--Contains horizontal, vertical and fold mirror motors, heating elements, auto dimming and also horizontal and vertical position sensors if equipped. |
| • | DRIVER DR MOD 10 A fuse |
| • | FRT PASS DR MOD 15 A fuse |
Outside Rearview Mirror Controls
For non memory mirrors, the outside rearview mirrors are controlled by the driver door switch assembly (DDSA) which contains the mirror control switches. 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.
For memory mirror applications, the mirrors can be controlled as outlined above or by any of the following:
| • | A keyless entry unlock transmission--Which will position the mirrors, among other features, to predetermined positions for up to two different drivers |
| • | A passive keyless entry command--Upon opening the driver door, to predetermined positions for up to two different drivers |
| • | A memory recall activation through the radio |
| • | A voice activation memory recall through the navigation radio |
Outside Rearview Mirror Operation
The mirror select switch is used to select the mirror to be adjusted. The mirror direction switch is used to control the mirror in a specific direction. These are both direct inputs to the DDSA. The DDSA reports the activation of these switches to the
DDM and PDM via the GMLAN serial data circuit.
The DDM and PDM upon receipt of the GMLAN message, will provide battery voltage and ground to the appropriate mirror motor control circuits to move the mirror glass. The DDM and PDM will reverse the polarity of the voltage and ground it applies to the
mirror motor control circuits in order to run the motor in opposite directions.
Outside Rearview Mirror Memory Operation
Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The DDM and PDM supplies a reference voltage and a low reference to these sensors and determines mirror position through the horizontal and vertical
position signal circuits. 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. 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.
Outside Rearview Mirror Tilt in Reverse Operation
The DDM and PDM communicate with the Instrument Panel Cluster (IPC) over the GMLAN serial data circuit. When the gear selector is shifted to reverse, the PCM transmits this status via a GMLAN message to the IPC. The IPC then transmits the reverse status
message to the DDM and PDM, which apply voltage and ground to the vertical motors of the outside rearview mirrors to tilt the mirror faces down 7 degrees. This allows the driver to see the curb while parallel parking. When the gear selector is shifted
out of reverse, the DDM and PDM will control the vertical mirror motors to return the mirror faces to their previous positions.
Outside Rearview Mirror Defrost Operation
The outside rearview mirrors heat during the rear window defogger cycles for the rear window. The heated mirrors are connected to the DDM and PDM. The DDM and the PDM receive a GMLAN serial data message from the HVAC control module indicating that the
rear window defogger switch has been activated. If conditions are correct, the DDM and PDM will apply battery voltage to the outside rearview mirror heating element supply circuits, and ground to the return circuits. Under certain voltage conditions the Instrument
Panel Module (IPM) may send a message to the DDM and PDM to conserve voltage and the heated mirrors may be cycled ON and OFF until operating conditions improve. For more information about the rear window defogger system refer to
Rear Window Defogger Description and Operation
.
Outside Rearview Mirror Power Folding Operation
The operator may simultaneously retract both mirrors to a fully folded position, in which they are closely tucked in and parallel to the front door windows, or simultaneously extend both mirrors to the fully unfolded position for normal driving.
For this feature, the DDSA has an additional power folding mirror switch built into it and each mirror contains an additional power folding mirror motor. When the switch is activated to fold mirrors, the switch contacts close, the DDSA interprets the signal
input, and sends the command on to the DDM and PDM. The DDM and PDM each apply battery voltage and ground to the appropriate circuits of their respective power folding motor in order to retract the 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 to move both mirrors to the fully extended position.
The power folding mirror switch is a one position momentarily switch. Each press will activate the mirrors in the opposite direction.
