ABS Comes and Goes Question-Update
Updated 15 May-- Hoping to get an idea from experts here what is likely happening before I give a garage an open-ended job order to find and fix it. 2003 Chev 2500HD 6.0 Gas. For the last while...
Forum Discussion
I had a 2004 that also developed an odd ABS issue. It never popped an ABS light, but under 10MPH the ABS would kick in and it felt like I lost my brakes. The issue was the point where the ABS sensor was bolted to the front wheel hubs. These are known to get thick corrosion under the plastic sensor. This corrosion lifts the sensor to the point that it sets too far away from the tone ring that's inside the hub assembly causing the sensor to loose signal at low speed. This tricks the ECM into thinking there is a difference in speed between front and rear so it kicks in the ABS.
The fix is to remove the wheel speed sensors and use a stif wire brush and/or a scraper to remove the thick rust. Once it's clean use a good rust inhibiting paint on the hub and reinstall the sensor. Be sure to plug the sensor hole so you don't get rust and grime inside the hub. After this you have good signal to the sensor and all is good.
The fix is to remove the wheel speed sensors and use a stif wire brush and/or a scraper to remove the thick rust. Once it's clean use a good rust inhibiting paint on the hub and reinstall the sensor. Be sure to plug the sensor hole so you don't get rust and grime inside the hub. After this you have good signal to the sensor and all is good.
