anyone know about warninng light for brake pads?
Just had a new warning light come on my E46 M3 with 109,000 miles, round circle with lines on outside of it. M3 Manual say check brake pads. Brakes work fine. Pads replaced 20,000 miles ago. Got 70,000 miles on first set of pads. Anyone have this happen to them? WHAT DOES IT MEAN? HOW TO FIX IT?
sensor is worn or broken off or loose?
replacing the sensors is easy
They are located on the left front and right rear inner brake pads. Once the wheel is off it only takes needle nose pliers and possibly a flat screw driver to get the old ones out. The connector at the suspension end also detaches easily with no tools. They cost $15-20 each.
The alarm goes off before the pads are fully worn out so the brakes should function fine for a short while. The pads should not wear out in 20K unless you do a lot of track events or if the caliper piston gets stuck "on". This is not uncommon in the northeast where they salt the roads heavily in the winter.
I would still check the inboard pads, just in case
There is one sensor on the inboard pad of the driver's side front, and one on the inboard pad of the passenger rear. The light will trip if either or both sensors are worn. It is possible that you may have caliper binding issues... so I wouldn't rule them out unless you have a good look first.
Other than that, the sensors themselves are an inexpensive fix (About $18 per).
Hope this helps.