My fuel gauge goes from half to empty what can I do to fix the problem

Hello, The fuel level sending unit, fuel gauge, or the circuit is most likely to have the issue. The sending unit does pass this information through the body control module, but unless other problems exist, this is less likely. Test the fuel level sending unit by monitoring the output voltage while you lift and lower the arm and float assembly. If the voltage doesn't change, or is intermittent, bad sending unit. However, check the wiring as well, especially if the sensing unit works properly. A bare portion of wire could be grounding at random.