Conditions for Setting the DTC: P0068
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, and 2010 Chevrolet 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.