Theory Of Operation
WARNING: This page is about a different car, the 2025 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The Transmission Control Module (TCM) monitors the Controller Area Network (CAN) FD Bus and Private CAN Bus circuits for failures. This Diagnostic Trouble Code (DTC) sets when there is a problem with both CAN Busses and the TCM can not receive data from the Electronic Shift Module (ESM) to determine the shifter position.