Circuit/System Description
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Battery positive voltage is supplied to the memory switch from the driver door module (DDM). When a memory switch is pressed, battery voltage is applied through the switch contacts, a series of resistors and thorough the memory switch signal circuit to the DDM. The door module then sends a message via the GMLAN serial data line to the memory seat module (MSM) indicating the memory recall request. The MSM then commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory in response to the switch input.