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.
The TAP Shift/Driver Shift Control (DSC) allows the driver to shift gears by using the TAP switches located on the automatic transmission shifter. Pushing forward on the shifter will command an upshift and pulling back will command a downshift. Ignition voltage flows from the ignition 3 fuse through the TAP Switch resistor array to the Transmission Control Module (TCM). The TAP system is activated when the gear shift lever is in the D position and moved over into the DSC gate area. When the shifter is moved over into the DSC gate area, the TAP enable switch is closed and completes the TAP enable circuit from the Body Control Module (BCM) to ground.