Conditions for Setting the DTC: P2138
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 voltage difference between APP sensor 1 and APP sensor 2 exceeds a value of 2 percent for more than 0.3 second.