Theory Of Operation
WARNING: This page is about a different car, the 2016 RAM 3500 HD and 2016 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) receives a constant voltage from the Batteries through the Battery wires that are connected directly to the positive (+) Battery post. The PCM receives Ignition Switch input when the vehicle is turned on. The PCM will illuminate the Malfunction Indicator Lamp (MIL) immediately after the diagnostic runs and fails. During this time the customer may experience some performance effects such as engine dying or hard starting. Fault Information and Trip Information may be inaccurate.