I have the same error message after loading 2021 Yukon XL AT4 for the first time. Loaded with ski gear suitcases etc for road trip. Engine off. Had raised and lowered the air suspension several times and worked fine up until loading
We got ours back from the dealership yesterday and, yes, all it needed was a reset. Working great over the last 36 hours. Silly problem to have, but glad it was easy enough to rectify.
Got mine back , it was just a reset but speaking to the service tech they aren’t sure what the real issue is. I’m back at normal ride height now and plan to leave it there .