You can pull the brake pad sensor off the back of the brake pad to see if it's worn. Often people will swap a worn sensor onto new pads or the pad is worn out.

If the pad and sensor was replaced, you still need to reset the system.

Meausured Ω across the sensor should read open not shorted.

__________________
2011 E70 • N55 (me)
2012 E70 • N63 (wife)