Abs Come On At Low Speed Stop

[zachary00]

I had some problems with the abs coming on below 5 mph when making a stop. I took it to the shop and they said there was a tsb for cleaning the front wheel speed sensor. They cleaned them and said when they scanned the computer it did not return any codes (implying all where good). When leaving the shop the abs continued to come on at low speeds. They said the front left hub needed to be replaced, and when done it would stop. I replaced the hub today (it came with a speed sensor in it) with no success on the abs. At high speeds, or hard stops, there are no problems at all. Since it started I replaced the rear pads simply because it was time to change them. What could be causing this? It also has a new rear speed sensor from when I did a repair on the transfer case. The abs lights are not on. Front brake pads are less than a year old and fewer than 10k miles on them.

 

2005 chevy silverado 2500 hd 4x4 with 6.0

[SouthCo]

Not sure but the shop you are using should be refunding you some money for replacing stuff that wasn't the culprit.

[asc08]

http://www.gm-trucks.com/forums/index.php?showtopic=131460

 

There are many posts on this. As was pointed out to me, check the voltage of the sensor output while rotating the hub by hand. Should be greater than .350 volts, AC. Clean the mounting surface under the sensor very well, add some anti-seize, or corrosion protection, and re-install. Be sure to plug the hole while working on it to prevent debris from getting in there.

[zachary00]

I realized after the fact that this has been beat to death. I should have done a search first. I appologize. I feel I need to add something to this post, so here it is. I found this website searching google. If it is something that shouldn't be on here, let me know, or delete it. It is pretty helpful. Like I said, it came up in a google search. Nothing I have personally.

http://ww2.justanswer.com/uploads/GMGreatW..._kicking_in.pdf

[asc08]

I would concentrate on the hub that was not replaced, since the new hub should be free from corrosion.

 

Follow the procedure that you posted. After you get the wheel and brakes off, connect a voltage meter to the connector on the wheel speed sensor. Spin the hub by hand and see what the voltage is. It should be .350 VAC (350 millivolts AC). If it is low, remove the wheel speed sensor, and clean the bottom of it well to make sure there is no debris on it. Plug the hole in the hub (I used a foam ear plug that I got from work, as suggested by another poster here), and clean the surface of the hub well. Put the sensor back in and do the voltage test again.

 

I made the mistake of putting it all back together, realized I still had the problem, repeated it, with the voltage test, failed (.1 VAC), then really cleaned the surface down to good shiny bare metal, applied some anti-seize to the surface, and all was good.