99 silverado abs comes on 5mph or less

[gmcjohnny]

For the past year I have drove around with the abs module unplugged (motor got burned up due to the common problem from getting wet). During the past year I replaced all four rotors and pads. I recently had a new EBCM installed. Now when I am coming to a stop during the last few mph the abs kicks on. It is very scary at times because I have to pump the brakes to get it to turn off or else I do not stop that quick. I called my local garage where the ebcm was put on, they say I need to replace one of the hub / bearing assembly in the front. But I have noticed on a posting that it could possibly be a wheel speed sensor? Any thoughts?? Thanks!

[99ssconv]

a snapshot with a scan tool would isolate which sensor is dropping out. check the front wheel bearing for play, i had one with a loose rf wheel bearing and had the same symptoms you are talking about.

[99ssconv]

also check the abs harness that runs next to the a/c compressor, seen a few where the harness was contacting the clutch hub and rubbed through the wires

[dieselman]

Ok Did you plug the abs motor back in so the abs light was out and working. If so you have a sensor gone and it is part of the hub also very hard to pinpoint with a scanner you will need two pepole one to drive and one to watch the scanner. You have three sensors for the abs two front one back. If you want to be safe till you can get it fixed just unplug the drivers side abs sensor located under the hood on top of the control arm. this will set the abs light on but you will not have the abs comming on at low speed. Hope this helps

[sparhawk56]

I had the same problem with my 99 Silverado. It turned out to be the wheel sensors. I read a bulletin somewhere, unplug the wheel sensors and hook a meter up, you should measure > 250 mV AC when spinning the hub by hand (I'm not 100% positive about the 250). I read about 110 on mine. I pulled out the sensor (carefully), cleaned below it with a wire brush, put it back in, and the reading went up to 400. The problem went away as well. Sparhawk56