The switch that failed and generated this diagnostic trouble code (DTC) is a built in part of the driver door switch assembly (DDSA). There are no external circuits. The DDSA contains a microprocessor which takes the signal generated by the switch contacts and assigns a digital message to it. The DDSA then sends this message over the Serial Data Class 2 communications line to the driver door module (DDM) to move the left mirror, or, to the passenger front door module (PDM), to move the right mirror. The DDM or PDM then applies voltage and ground to the appropriate circuits of the appropriate mirror motor to move the mirror vertically and/or horizontally. The mirror motors are reversible.

It should be noted that, when a contact for a mirror position has failed, it will affect both mirrors.

The self diagnostic test runs once every 300 milliseconds regardless of source voltage.

If the DDSA detects that the switch contacts are closed for more than 30 continuous seconds, it sets the DTC.

The DDSA deactivates and ignores inputs from the failed switch contacts and stops sending messages for the failed contacts to the DDM and the PDM. The DDSA will continue to respond to inputs from other non-failed switch contacts.

The DDSA clears the current DTC when the switch status changes.

A sticking switch can cause this DTC to intermittently set current.