FMI 501 CAT Fault Code

Cause :

The battery supplies electricity to the TCM even when the ignition switch is off. This power allows the TCM to store data such as DTC history and freeze frame data.The Engine and Transmission System is not performing as expected. An issue has been detected in the Engine Electrical System, including the Charging and Starting System that monitors and controls the engine starting system and 12V battery charging system.