I have an Astra G z16se. Keeps going into limp mode intermittently. Hooked up the Bluetooth opcom and got code P1230-A Main relay stuck open. Is this code to do with the fuel pump relay (purple one)?. Are the Main relay and fuel pump relay the same?. Also checking the readings and the oil pressure seems to be always low, is that normal? Forgot to mention it auto revs to 1500rpm and stays there.