Conditions for Setting the DTC: P0989
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.
The TCM detects that the TFP Switch 5 signal voltage remains low, 0 volts when the low and reverse clutch or the 4-5-6 clutch is commanded ON.