Just to follow up, the local automotive repair shop diagnosed my problem as failed front shocks...$1700 dollars to replace. I paid it, then found out they replaced the front shocks plus they didn't tell me they replaced the left rear, too (same position as Wild Bill's). I noticed that one was replaced on my own a day later. When I went back and asked them about it, they said they replaced it "on their dime because changing the front shocks helped, but didn't totally solve the problem." Trust = low. I was rushed for time as I was headed out on a 2000 mile vacation the next week, but now I think I would do it for myself. All except the front coil squeezes and the ride height trim procedure. Can anyone recommend a mid-level ODB2 scanner that can perform this reset on my 2018 Tahoe? I saw this vid from Xineering LLC that shows an Autel MaxiDAS DS808 can do it...is there anything cheaper?