Last weekend I took my '01 vert thru a car wash. Immediately afterwards there was a buzzing coming from the gauges, it only went away after restarting the car. And only came back one more time that day.

The buzz stayed away until yesterday, now it's back. It comes on sporadically and when it's happening it's tied directly to the gas pedal. When I lift off the gas to shift it stops and then restarts immediately upon acceleration.

If I shut the car off and restart it and stays off for a few minutes.

I have not scanned for codes.

All fluids levels are correct.

Nothing shows in the DIC.

???

 

C5s are now somewhere between 13 to 20 years old. They were manufactured with a lot of advanced technology features (for that time period) and most all of them depend on electrical circuits of some sort. Because of that, it is highly recommended to not run our cars through car washes as those have some extremely high pressure water sprayers that work on your car from just about every direction (over, under, sides, etc). Those high pressure sprays can get into the electrical circuits and cause all sorts of havoc and I think that's what has happened to you. If the DIC is showing no codes (quick question, did you have any NO COMMS show up in the DIC?) then you're going to have to trouble shoot your problems by manually tracing the wiring. You might require an assistant to help as well. Just from basic knowledge, most buzzing sounds come from relays. There are two panels in the C5 that have relays, one under the hood and on in the passenger foot well. You might start by seeing if you can locate a buzzing relay with someone activating the gas pedal while you do the detective work. Another question. Did you wash the engine bay at the car wash? Your problem might be as simple as waiting for a component to dry out on its own but be warned, high pressure washing near the engine bay or underneath the car can be hazardous to your car and mental health. GL with your search. Let us know what you find.