Conditions for Setting the DTC: P0068
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 ECM detects that the throttle position and the indicated engine load do not correspond with the expected load and throttle position for less than 1 second.