The "Check brake pads" light came on in my 95 325is yesterday on the way home from work. I decided to change the pads front and back because I hadn't done it on this car yet. I got all the new pads on without much difficulty and re-used the pad wear sensors. They didn't look damaged although there were a few cracks in the wire insulation. No bare wires showing though. I took it for a test drive afterward and everything seemed OK. No more warning light. Well, on the way to work today, after about 10 minutes of driving, the red warning light came on again! Now there's definitely nothing wrong with the pads... And yes, I checked the brake fluid level after I finished the job. The sensors appear to be some sort of magnetic pickup device that probably detects when the pad reaches a certain distance from the rotor, indicating time to replace. Do they go "bad" as a rule? Do you need to replace them along with the brake pads? Is there some sort of reset you need to do once the warning light goes on? I'm not one for just replacing parts without a reason... Thanks for any insight.