[E90Fleet]

The brakes use a combination of mileage, fuel usage and sensors to determine the interval displayed.

These cars have 2 stage sensors.
So with new pads the car just uses estimates to determine the interval, then later the first stage of the sensor is worn through, so the car corrects its estimate because now it knows exactly how much pad is left instead of estimating it.

The car then displays its 2nd estimate untill the 2nd stage of the sensor is worn, which is at about 3mm. When this is reached you get a permanent indicator telling you the pads need changing

Dealers will also check the pads at certain services and will replace if they have 3,5mm left.


So this is the basic sequence for new pads
1) Estimated mileage life remaining based on new pad.
2) First sensors wears and corrects estimation.
3) Estimated mileage life remaining based on update from sensor 1.
4) 2nd Sensor worn and full time change pads warning displayed.