Power Mirror Switch: Description and Operation

OUTSIDE REARVIEW MIRROR SWITCHES
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 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.

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. When the contacts close, voltage flows through them to ground and the DDSA interprets this as a specific mirror direction request signal. The DDSA then sends the request to the appropriate door module via the class 2 serial data circuit.

The Mirror Position Switch contacts are designated as Left-Up, Left-Down, Right-Up, and Right-Down. When the switch is activated in a Left-Up, Left-Down, Right-Up, or Right-Down direction, the switch closes the corresponding set of contacts, the DDSA interprets the signal and sends the information, via the class 2 serial data circuit, to the appropriate front door module, DDM or PDM. However, when the switch is activated in a direct Up, Down, Left, or Right direction, two sets of the contacts are closed. The DDSA recognizes the two contact signal as a one direction signal in the direction common to the two signals. For example, when the switch is activated to the Up direction, both the Left-Up and the Right-Up contacts are closed. The direction common to the two sets of contacts is Up. The DDSA interprets this signal as an Up command and sends the information, via the class 2 serial data circuit, to the appropriate front door module. Once the appropriate front door module receives the request, it moves the associated mirror to the requested position.

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.