You have a warped brake rotor. A pulsating brake pedal on stopping is a classic symptom.

 

 

Put a dial indicator on each rotor, that will tell you if one is warped or not. You will then eliminate or confirm that as a problem.

 

Thanks again for your response. I will definitely check the rotors. I still don't think that is the issue because if a rotor was warped it would always vibrate like that not just when the 3 warning lights are off. When the ABS, low tire pressure and DSC lights are on, the brakes function completely normal and are actually pretty impressive.

 

I have no idea if this is the reason, but the brake wear sensors are notorious for failing - I had to replace two myself at 50K. I'd just get it scanned to see which one is bad or if thats a pita, just replace them. Get the oem ones, I've heard the aftermarket have their own issues.

 

The symptoms suggest intermittent failure of one of the 4 wheel speed sensors. Could also be badly corroded tone ring which is a part of the hub as I infer. Let suppose that for some reason one sensor did not get a pulse or two because those tooth one the tone ring is as rotted as in some British mouths , and that will definitely tell the ABS that wheel is spinning slower all of a sudden. What would you do if you are the ABS faithful servant? After all, Mini is British so rotted teeth is in the genes.

Not warped rotor as OP knows. Pad wear sensor has nothing to do with ABS, or low tire pressure warning.

 

Thanks for your input Subw00er and pnwR53S. As far as the brake wear sensors, I deleted those after they crumbled coming out of the previous worn pads. I trimmed the wires near the plug and heat shrink wrapped everything to keep that light off. I have the wheels off enough that I can monitor the brake pad wear the old fashion way. It seems like I need to get the wheel speed sensors sorted out and then go from there. The way that it is an intermittent failure is what is throwing me off the most. It is like something does not connect or register occasionally at start up and then it takes a mile or two to reconnect. I can tell at start up (before I have moved at all) when it is going to behave this way because after start up the ABS and DSC lights will not be on. The tire pressure light is never on after start up because it has to be driven a bit before it recognizes that there is a wheel speed sensor issue. When it is in the weird state the tire pressure light will not come on after driving a bit. It only comes back on when the ABS and DSC lights come back on. It is at that point that I know the system has reconnected or whatever and then everything works as normal.

 

 

Yes. The pad sensor can be wired off by shorting the two conductors. It is normally closed - signifies pads are good.

To OP. You just have to think how ABS, DSC, and flat tire monitor all work relying on the 4 wheel speed sensor. They all have their respective algorithm and ABS and DSC is most complex. Say if the tone ring has 60 teeth, that is 60 pulses per rev. An intermittent skipping of a couple will be detected by ABS and DSC as that wheel being slower than the rest, assuming the car is going straight. These algorithm has to be design to handle when the car is in a turn too, and crazy driver like me trying to crash it.

I infer the speed sensor just a dumb pick up coil, rather than something more sophisticated like Hall effect. Each has only two conductors. It is like a tape recording playback head. Please don't ask what a tape recorder is.

 

 

wait, so it could be a flat('ish) tire doing it?