Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The range selection mode (RSM), also known as the TAP Shift, allows the driver to manually shift gears by pressing the Plus/Minus button and select the desired range of gears for current driving conditions by using the RSM shift switch located on the automatic transmission gear shift lever. Pushing the Plus switch will command an upshift and pushing the Minus switch will command a downshift. A 12-volt reference voltage flows from the body control module (BCM) through the RSM switch resistor array to the BCM. The RSM shift system is activated when the gear selector is in the Manual (M) position. RSM system is deactivated in all other range positions.