[mark1996]

OK, here is the situation: 2009 328i with 54k miles. I do not have any warning lights on. The computer is showing that I have 24k miles left on the front pads and 9k miles left on the rear. However, the rear pads look thin and I want to go ahead and replace the rear pads now so I will not have to worry about them over the next 50k miles.

My questions:

1. If I replace the rear pads and (without disconnecting the wires) just zip tie the old sensor out of the caliper somewhere, will I not have to reset anything?

2. If I zip tie the rear sensor, will the computer still set off warning lights after the current 9k miles estimate is reached? Or will it just never set off any warning lights as long as the old sensor just sits there zip tied for the next 50k miles?

3. If I replace the rear sensor with a new one along with the new rear pads, will I have to reset the system? In other words, does disconnecting the old sensor and installing a new one trigger something that requires a reset?

4. If I replace the rear sensor with a new one, can the system be reset without having to mess with or replace the front sensor?

5. Is this whole brake sensor thing just a pain in the ass since our pads seem to be lasting well over 50k miles? I check my brakes every time I change from winter wheels/tires so they are checked about every 6 months. Can I just zip tie both the old front and rear sensors out of the way without disconnecting the wires and then never have to worry about resetting anything?

I have done a search and I have found many answers which are inconsistent and confusing.

[nesnith]

The brake sensor wears at the same rate as the brake pad. A new sensor pretty much has the same thickness as the pad. When the pad wears down, so does the sensor. Once the pad has worn down past the BMW-specified threshold, the sensor would then triggers idrive in the car for the brake service alert to come up.

If your brake service light is not lit, that means your pad has not worn down past the service threshold. If you change the pads now, you may keep your old sensor to save some money. Then, your idrive estimate will remain at its current mileage until your new pads have worn past the thickness of your old sensor.