FMI 137 CAT Fault Code

Cause :

If the battery voltage falls below a minimum level, these memories are cleared and the TCM determines that there is a malfunction in the power supply circuit. When the engine is next started, the TCM will illuminate the MIL and set the DTC.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.