AgBioBen

On my way to work I received the same error again. I reached my left foot up behind the dash and tapped a wiring harness and immediately the error disappeared and the gauge went back to normal. Now to figure out which one it was.

Bought a 2011 Silverado a few months ago, same problem. Changed the thermostat to be certain and there was nothing wrong with it. Now I have a flashcal and I checked the engine temp when this A/C off code came up and the temp is just fine 168 at the moment (even though the needle stays at 0) No other codes or problems. Like you I suspect it's wiring or a connection. Thanks for the heads up, I'm going to see if it's around the BCM as well.