I have a 99 S70 and the ABS kicks in at in appropriate times, and stays stuck on (i.e. the pedal vibrates every time I touch the pedal and I can hear a loud buzzing sound even if I am not applying the brakes). After a while, the noise stops, but the ABS and TRACS lights come on. The first time this happened my mechanic replaced the ABS module and the problem went away for a while. The problem has resurfaced and each time “fixes” the problem for free, but it keeps happening.
A) What is the root of the problem?
B) Can I fix this myself every time it happens in the future?
a) If your mechanic manages ‘fixes’ the problem, at least for a small time, ask him.
b) Than depends on what the mechanic does to ‘fix’ the problem. ABS and Traction Control systems are complex and have their own set of diagnostic codes. The solution could be a simple wipe or wiggle to an expensive overhaul.