Theory Of Operation
WARNING: This page is about a different car, the 2012 Dodge Caliber. However, it is still accessible from the selected car via links, so may be relevant.
The Transmission Control Module (TCM) receives two throttle position related signals over the CAN Bus. One is the throttle pedal position and the other is a throttle pedal position toggle bit. When the Toggle signal pattern is out of range from a predefined signal pattern a DTC will set.