My understating was the time/miles between first contact and the break measured how far you went between to estimate how many miles to set in the countdown. Not sure how it measured the difference with two wires but maybe grounded through the rotor.

In any event cutting and putting a jumper on my sensor lead worked to reset the sensor on my e70. There's about 3mm pad left I'll be changing them next week I just didn't want to be annoyed by idrive or worse have it get to some level that only the dealer can reset (that happened on my e53 with oil change countdown).

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