For both the on board control system and for utilising 3D be it Trimble or Leica?
If you are using an external full 3D system you will not need “Grade Control” enabled (that’s Caterpillar’s integrated full 3D system that is either factory installed or dealer installed option). If you are using your own 3D setup or not at all you will not need it, it costs a lot of money to enable it.
your problem is in wiring or sensors or the ECM itself, not options enabled or not.
Of course no favors have been done by the manufactures not clearly specifying what is what when it comes to this stuff and throwing everything under the generic heading of “grade control”