ABS Issues

dj_bosse · September 28, 2020

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.

Formulabruce · September 28, 2020

Oddly enough, the GM advice would be my advice. I have been down this road, and eventually changed out the front hubs with new sensors in them. It is Not that big a job. 1A auto has a good video on this. You can do this yourself for under 300 bucks.

Sometime rust or debris gets in where the sensor reads and causes this problem. Good luck!

dj_bosse · September 29, 2020

Thanks for the response. I do somewhat agree with that, however them charging $1500 for bearings is absurd. And I know I'd be able to do the job myself, but if I replace them and it doesn't fix the issue then I'm out the $300 in parts plus the $125 I paid to Chevy for them to give me the wrong diagnosis; then I'm in the same situation I'm currently in (just out $400). I guess I just would've expected Chevy to do a bit more digging into the problem (checking the sensor gap, seeing if the module is functioning, etc.) prior to just saying to do what the scan tool says.

And somewhat addressing your rust comment: I know rust can get in the hub, but I had zero ABS/brake issues prior to the wire being chewed. In my opinion, I would think if rust was causing my current issue, it would've caused issues prior to the wire being chewed. So while I can understand rust in the hub can be an issue, I'm just not sure I think that would be my case here.

diyer2 · September 29, 2020

For $300 I would try this. New complete hub bearing and sensor from Rock Auto. Timken SP580310 should work or the right parts.

Edited September 29, 2020 by diyer2

Formulabruce · September 30, 2020

Also, bearing vibration can cause this symptom.

There is a 90% chance a new hub bearing/sensor will solve your issue.

mjm-1957 · September 30, 2020

Get a good scan tool and go to ABS data. Have some one else drive and watch the wheel speeds as you come to a slow stop. You will see one wheel speed drop to zero and thats what the ebcm is seeing as a locked wheel and activating the ABS.Thats the bad hub bearing.We are in NY and have issues from salt and corrosion and deal with this alot. Hope this helps.

dj_bosse · September 30, 2020

I've already run scan data and both front wheel speeds drop out as I'm slowing down. I ended up ordering new bearings and will replace them myself once I get back in town. If it doesn't fix the issue I'll likely report back here for second thoughts. Thanks for the feedback.

dj_bosse · January 17, 2021

Sorry to bring back an old thread, but thought I'd give an update on this. After many delays I finally got around to replacing the bearings. Long story short, it didn't fix the problem.

jnissen · January 24, 2021

I know early brake controller were plagued with cold solder joints inside the control module. I don't think the 2006 was affected but thought I would throw that out there.