My 2006 GMC Yukon started having brake issues out of nowhere, brakes up front  started locking up thankfully I was pulling out of a parking spot and noticed it quick and stopped.Keep in mind it’s also a 2WD with power to the back wheels so transmission problems are out the question, I noticed the brakes upfront grinding to a halt as well as skid marks on the wheel from the brakes locking up. I tried to drive again to see if the problem consisted and it did so I got it towed to my house.   I had already checked the brake fluid and the wiring connections to the brakes to see if anything was loose. which it wasn’t, then I decided to take the left front wheel to inspect the brake it seem to be fine it  don’t have any unusual wear and I spun the front tires to see if the tires made any unsual noise, brakes engage fine.  everything looked fine. So I test drove it around the block to see if it would happen again and it drove down the road fine and started locking up again, and a message came up on the dash that said “Traction” or “Traction Active”  took it home slowly and tried to do more research on it. I know nothing looked or sounded out of order on my brakes but I could be wrong I think it had something to do with a traction sensor? Or maybe wiring?