Theory Of Operation
WARNING: This page is about a different car, the 2020 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.
The purpose of the diagnostic is to detect a failure in the mechanical linkage between the shift lever and the manual valve. The manual valve is integrated in the Hydraulic Control Unit (HCU) and is mechanically linked to the shift lever. A mechanical failure in the linkage between the shift lever and the manual valve can result in an unexpected power flow, especially if the Limp Home Mode Valve (LHMV) has failed. This diagnostic checks the input speed while the transmission is in the PARK position. The monitoring is performed once per trip after an engine restart.