My GUESS is that one of the ABS sensors at the wheels is either going bad or it is dirty. How they work is this. It is called a hall effect. There is a magnet in the sensor which is stationary. As the wheel turns, there is a stater that turns with the wheel. When you have a magnet that passes over a conductor, it creates a current. Imagine the magnet being passed by several conductors as the wheel spins. The current that is produced tells the computer that everything is fine. When a wheel skids, the wheel stops spinning. Thus, the current is lost and the computer turns on the abs to release brake pressure to affected wheel. Since it only happens when going slow, my guess is there is something that is not allowing the current to be sent to the computer. It could be dirt or a faulty sensor. As a result, the ABS is actuated and you feel the vibration.
Did that make sense? Lol
Tuesday, September 9th, 2014 AT 5:40 PM