I have a 2006 Silverado 2500HD with 57xxx miles and have been having ABS issues for the past couple months. I was driving down the highway one day and the clip holding the wheel speed sensor for the passenger front wheel broke and the rim rubbed through the wire. When the wired chewed through, the ABS light came on (code C0035/40 for front left/right speed sensors). When I got home, I started checking stuff out and noticed I had some loose ball joints and some play in the tie rods, so I replaced all ball joints/tie rods/stabilizer links, and also replaced the wheel speed sensors for both sides (driver's front clip was also broken, so figured it was a matter of time before it chewed the wire). On my test drive, the first time I slowed for a stop sign the ABS light came on. Once I was under 30mph the brake light also illuminated on the dash. I tested the resistance of the new speed sensors and they were slightly higher than the factory spec, so I thought maybe I just got defective sensors (ACDelco from Rockauto). After getting the warranteed sensors, the new ones had the same issue, although the resistance tested within the spec provided by GM. I decided I may be above my head, so I took it to trusted a shop. The shop tested resistance on the sensors, agreed with my conclusion, and tested the output from the brake module. They believe somehow the brake module shorted out and there's an issue coming from the module below 30mph such that it can't read the wheel speeds, and then activates the ABS/brake lights. They also said if it is the brake module, that Chevy is the only one who's able to program them, so I may be better off just taking it to Chevy rather than making them be the middle man.
So I took it to Chevy (fully expected them to charge an arm and leg for the repair) and I don't quite agree with their diagnosis, so thought I'd ask for some feedback on the forum. They are saying I just need to replace the front wheel bearings (including the speed sensors). They also want to charge $1500 to do this. Being that the speed sensors are new and verified to be working, is it reasonable to conclude that replacing the bearings won't fix the issue? Only reason I could think this could fix the issue is if the gap on the sensor isn't correct. But then again, if that's the case, I'm wondering why they don't just fix the gap on the sensors (apart from trying to take an extra $1300 from me). Maybe I'm just being paranoid about them trying to take advantage of me, but I'd hate to go through with this repair and the issue not be fixed. I appreciate any thoughts.