Manual Downshifts
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.
Manual downshift testing is not required for vehicles equipped with Driver Shift Control (DSC). The TCM and shift solenoids will automatically override DSC downshifts to protect the transmission from damage.