Shift Stabilization Description and Operation

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Shift stabilization is a function within the vehicle's software/calibration that determines if and when to prevent upshifts under load. The purpose of shift stabilization is to reduce shift busyness during conditions that would otherwise produce frequent upshifts and downshifts, such as trailering, operating on grades or at higher altitudes.

Shift stabilization calculates the required torque at the wheels in the current gear as well as the maximum torque available at the wheels in the next higher gear. If the torque in the higher gear is not sufficient, the transmission will remain in the current gear. If the torque in the higher gear is greater than or equal to the required torque, then an upshift is allowed.

Shift stabilization is active in normal driving mode, cruise mode, and in tow/haul mode. However, shift stabilization will be disabled during high throttle maneuvers, and may be disengaged momentarily if the cruise control "decrease" button is tapped or held, or if a significant "bump" in the road is encountered.