Theory Of Operation
WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
The purpose of the diagnostic is to monitor the park sense circuit from the Radio Frequency (RF) Hub. The RF Hub supplies B (+) on the park circuit to the Transmission Control Module (TCM). When the transmission is in park, the TCM will ground the park circuit indicating to the RF Hub that the transmission is in park. If the TCM detects an open or short to ground on the park circuit, a Diagnostic Trouble Code (DTC) will set.