Suggest you click "Notify Moderator" and ask to move this to Tech Issues. Not 'cause it's a Fiver and this is Class C, but because a genny can be in anything and Tech is where some of our Genny Gurus hang out.
Generac isn't as popular as Onan, so might take awhile to hear from somebody. Be sure to post the full Model Number. If there's a Manufacture Date, suggest you include that.
Finally, there's Smokstak.com which includes gennys and within that includes Generac.
Remember, even though most RV gennys run at a certain RPM, they still "idle" at that RPM if there's no load. At least in gasoline gennys, there's an "idle circuit" in the carburetor and its passages are even smaller than those in the power circuit. This means it's possible for a genny to carry a load yet not be able to run no-load. I had that exact situation with our Onan 4KW 3600RPM gas genny. Sometimes the carb can be cleaned and adjusted. I had to replace ours.
EDIT: I like ronf's comment above. With older gennys, those without solid state logic control boards and electronic voltage regulation, Cycles (hZ) and Voltage were "wound" into the build of the genny. If it produced 60hZ and/or 120VAC (whichever you had a meter that could display it) then it WAS at 1800 or 3600RPM. Likewise if you had a tachometer, if you could verify it was at 1800 or 3600RPM, you didn't need any other test equipment to know it was at 60hZ/120VAC. But you have some form of electronics capable of displaying that "14" so you may need more tools, more help.
Easiest thing to do might be make sure all the mechanical linkages are completely clean and free. If it can't get back to idle, it's likely to trigger that code and shut down.
