friend has a 2004 with the same problem.
Does your HVAC work?
Do you have an aftermarket radio?
Well, anyways his gauge problem started after he put a new HU in with the proper kit to all that may ask, even ran the new relay for power.
We traced his HVAC problem to an error in the body control module, (blower motor, resistor, and hvac unit have either been replaced or tested) BCM codes came from a Genisys evo scanner.
We are not sure yet if the BCM is related to his gauges yet or not. Havnt had the time to diagnose further,
I know that this is not an answer to your question, but I thought I would ask and share info.
