Conditions for Setting the DTC: P0797
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The TCM detects an incorrect off-going clutch gear ratio, or tie-up, when the low and reverse/4-5-6 clutch is commanded ON for 0.5 seconds and the transmission input shaft speed is greater than 40 RPM from the anticipated input shaft speed.