Conditions for Setting the DTC: P2176
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 difference between the predicted and the actual throttle position is more than a calibrated amount for more than 1.5 seconds.