FMI 85 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.Associated with low engine fluid pressure. The reason most likely is the lack of oil in the engine, so first of all you need to check the amount of consumable. You should also make sure that the engine fluid pressure sensor is working.