2006 525i
103K


I replaced my front brake pad 3-4 years ago. During the entire time since then the computer indicated 49,000 miles to go, until a few weeks ago when that number changed to 2,000 miles and the countdown started (now at 480 miles). Does anyone know how much actual pad remains once the sensor countdown starts? I plan to replace the front pads soon, but if there's really 2-6 more months of safe braking remaining, that would be nice to know. The computer doesn't seem to be taking driving conditions into account as the countdown happens, but rather just seems to be waiting until an additional 2000 miles are driven (regardless of the amount of braking that occurs) before it displays a warning. Does anyone have any insight? Thanks in advance.

 

Just did mine a month ago and my display indicated -800 miles for front brakes (yes, that is negative and the color of the display turned from yellow to red). when I got the pads off there was less than 20% left but easily another 5-7000 miles

 

As I understood it the sensor has multiple resistance stages. You cannot reset the padwear mileage unless you have a brand new unworn sensor with the first stage intact. Then it always resets to the default milage remaining, and as each stage in the sensor is worn off and the resistance changes, it calculates the rate of wear from the actual driven distance since the last stage, and updates the predicted pad life.

 

I did not check a 5 series brake sensor mechanism. On the E46 3 series, if the pad is not replaced on time, the sensor wear out and eventually it will be totally disconnected and needs to be replaced. If 5 series has the similar mechanism, it is better to replace earlier. Otherwise, you need to pay for the sensor. You can check how much the pad life remain by looking at the pad through the wheel spoke.

 

My rear says 4000 miles but the pads are at less than 3 mm. The rotors are under minimum spec by 2 mm. I think when the sensor is worn out you are at the minimum brake caliper piston distance on the caliper