Don't know if you guys are still looking for answers for the yellow service brake light w/o mileage. I just changed my brakes today (rear) and ran into this problem. Basically I replaced my rear pads w/o replacing the sensor, and then reset the yellow service brake light (which at the time still had about 1000 miles on it). After resetting it, the yellow brake service light remain lit but w/o mileage. Furthermore, I got the car on the red car on the lift light along with the red service light.
The good thing is that I have a rear sensor handy, but originally I decided not to change it to see if I could get away with it since it was not triggered. So I took out the old sensor and replaced with the new one. After that, I reset the yellow service brake light, and it registered 30,000 miles. And after a while the red car on the lift light and the red brake light was also cleared.
So... the moral of the story is that one must always replace the sensor with the pads. I know that there are plenty of posts that says this... but I guess I just have to learn it the hard way. Also I find the BC brake service indicator to be pretty useless. I took the pads out and they still had quit a bit of life in them... I think next time I am just going to wait until the brake sensor get's tripped, since they have to be replaced anyways regardless if they are tripped or not.
Last edited by bimmernoob; 06-07-2010 at 11:58 AM.