[hotwired78]

All,

I followed the instructions to reset maintenance intervals and it worked fine. However, for some reason the maintenance date did not reset. Weird. I reset it before the service light ever appeared, as I imagine I will probably be doing this most of the time to get ahead of the long maintenance cycles suggested by the car. Also I will be doing the same for the brake pads, as the brake pad sensor is only an inaccurate estimation, and not really sensing pad width or rotor width.


Anyone else experience this issue?

IE: My brake fluid now says 50k miles, but still due in 09/2014.

[Efthreeoh]

Originally Posted by hotwired78

All,

I followed the instructions to reset maintenance intervals and it worked fine. However, for some reason the maintenance date did not reset. Weird. I reset it before the service light ever appeared, as I imagine I will probably be doing this most of the time to get ahead of the long maintenance cycles suggested by the car. Also I will be doing the same for the brake pads, as the brake pad sensor is only an inaccurate estimation, and not really sensing pad width or rotor width.


Anyone else experience this issue?

IE: My brake fluid now says 50k miles, but still due in 09/2014.

Not sure what you did as far as maintenance resets, but the brake fluid change is strickly 24-months from date of manufacture (for the first one), then 24-months from the date that last flush was performed and the CBS re-set. It never goes by mileage.

As far as brake pads, the brake wear sensor very accurate in determining when the pads are spent because it triggers the "BRAKE" indicator light once the wear sensor is consumed. The CBS estimate of remiaing pad life can be somewhat inaccurate if the car is driven differently as it ages (i.e. switching from city driving to primarily highway driving). When the "BRAKE" indicator lights and stays on, the CBS will read -- for the axle that the pads are worn out on. There is no need to change the pads early thinking the CBS estimate is inaccurate. when the "BRAKE" light comes on and stays on, it's time to change the pads.

My car has 249K, I've followed the CBS maintenance schedule.

[hotwired78]

Originally Posted by Efthreeoh

Not sure what you did as far as maintenance resets, but the brake fluid change is strickly 24-months from date of manufacture (for the first one), then 24-months from the date that last flush was performed and the CBS re-set. It never goes by mileage.

As far as brake pads, the brake wear sensor very accurate in determining when the pads are spent because it triggers the "BRAKE" indicator light once the wear sensor is consumed. The CBS estimate of remiaing pad life can be somewhat inaccurate if the car is driven differently as it ages (i.e. switching from city driving to primarily highway driving). When the "BRAKE" indicator lights and stays on, the CBS will read -- for the axle that the pads are worn out on. There is no need to change the pads early thinking the CBS estimate is inaccurate. when the "BRAKE" light comes on and stays on, it's time to change the pads.

My car has 249K, I've followed the CBS maintenance schedule.

True. I've simply had my pad and rotor measured and inspected. So I know I'm due.

Just wondering if there is a way to reset or modify the service interval, or service due date. or even just to reset the service interval before it starts the service reminder.

[Efthreeoh]

Originally Posted by hotwired78

True. I've simply had my pad and rotor measured and inspected. So I know I'm due.

Just wondering if there is a way to reset or modify the service interval, or service due date. or even just to reset the service interval before it starts the service reminder.

I don't what know more to tell you. I've explained how the system works. There is no need to measure the pads because the brake pad sensor does that for you. If the brakes have been maintained correctly, meaning the pads were not changed before the sensor was consumed and not changed with the new pads (you always replace the sensor when replacing pads regardless if the pads are at minimum thickness), then the system is giving you a somewhat accurate estimate of remaining pad life. However, regardless of what the mileage estimate is indicating, once the "BRAKE" light illuminates and stays on, the pads are spent and need replacement.

It is always good practice with BMWs to replace the rotors when replacing spent pads, since the rotors usually thin out before the new set of pads are spent, so measuring rotors is really not necessary either. If the rotor on your car was not changed with the last pad change then it may be worn to beyond minimum thickness. If that is the case, the I suggest replacing the rotors, pads, and sensor, and re-set the system.


You can't adjust how the CBS determines the pad life estimate because it is an algorithm built into the computer module that monitors the brake system. The sensor is dual stage, which means it has two wires in it. Once breaks midway through the pad life, the computer takes note of that event and adjusts the estimated remaining pad life (in mileage) until the second wire breaks and the sensor illuminates the "BRAKE" indicator, when the pads are spent.