2009 Chevrolet Avalanche Owner's Manual - Page 126

The vehicle has a shift stabilization feature that adjusts the transmission shifting to the current driving conditions in order to reduce rapid upshifts and downshifts. This shift stabilization feature is designed to determine, before making an upshift, if the engine will be able to maintain vehicle speed by analyzing things such as throttle position, vehicle load, and hill grade. If the shift stabilization feature determines that a current vehicle speed cannot be maintained, the transmission does not upshift and instead holds the current gear. In some cases, this may appear to be a delayed shift, however the transmission is operating normally. The vehicle's transmission uses adaptive shift controls. Adaptive shift controls continually compares key shift parameters to pre-programmed ideal shift conditions stored in the transmissions computer. The transmission constantly makes adjustments to improve vehicle performance according to the way the vehicle is being used, such as with a heavy load. During this adaptive shift controls process, some shifts may feel different as the transmission determines the best settings for a particular shift. Range Selection Mode On vehicles with a Range Selection Mode, this feature may be used to control the vehicle's transmission. To use this feature, do the following: 1. Move the shift lever to the M (Manual Mode). 2. Press the plus/minus button, to upshift or downshift selecting the desired range of gears for current driving conditions. 2-40