BMW Condition Based Service Interval - big change..

DriveSkill

Hi,

For the last couple of months my Condition Based Service (CBS) interval has been happily counting down from 15K->14K->12K and so on and it got to 11K about 2 weeks ago. However when I started it up on Sat it suddenly read 2,300km ! The 'offending' service item are the rear brake pads but not sure how they could go from 11K->2K in the space of a few days.

I started to suspect that maybe they got stuck on or even blaming my wife who has been driving the car during the couple of days for doing something! Apart from the CBS changing the car is driving fine and certainly the parking brake seems to be working and is not stuck on now at least!

Only other option I was considering was there is also a check due in June so maybe it just tried to calculate the mileage between now and June to sync them up but I don't think so....all the other service items are all still at the original mileage due amount (10s of K)

Anyone seen this before ?

Special Circumstances

I'd guess that the 11k was based on oil life / type of usage until some wear sensor tripped in the brakes.
I doubt* the system continuously monitors brake pad wear to the nearest 2mm - it has probably 2 states "Grand" or "on their way out".

*I've never heard of any sytem that does but hey it's a brave new world in automotive tech and I'm 10years behind the state of the art.

mickdw

I would have thought the brakes would be relying on a wear sensor and that is what has activated now.

DriveSkill

I agree they are relying on some sensor but I just thought it was strange to go from 11,000km to 2,300km in one step...btw it is continuing to reduce so now 2,200 etc so it does appear to be continuous monitoring and agree its just an indicator rather than a definite accurate mileage but still find the big jump odd...

George Dalton

The wear sensors on these are generally pretty spot on.

166man

Seems a bit strange, a quick look through the wheels, or if needs be, remove the wheel, should give an indication if the pads are worn or not.

Special Circumstances

Every days a school day - looks like they now use a 2 stage wear sensor rather than a basic one stage "Not worn / Worn".
Internet wisdom suggests that the computer registers the mileage the first one goes at, and when the the second one goes it can predict how much longer the pads are likely to last based on the mileage needed to wear from one to two. Or something to that effect.

myshirt

The condition based servicing on mine for the oil seems to go down 5,000 miles for every 3,000 driven. Never understood it.

Frynge

myshirt wrote: »

The condition based servicing on mine for the oil seems to go down 5,000 miles for every 3,000 driven. Never understood it.

Mine goes down 1000 km for about every 1100km driven so it might be how you drive it. I mainly do 100kph on motorways but now the weather is getting better there is a lovely shortcut I can take trough a mountain that is a great drive but low gears and higher revs do make my wallet lighter. Assuming I don't meet a tractor.

DriveSkill

Maybe my wife relies on heavy braking as she had it for the 3 days where it dropped Not sure I can tell her that her driving style costs 10x more brake pads than mine

Would be very interesting if I could drive economically again and it jumped back up to 10K left !!

Special Circumstances

DriveSkill wrote: »

Maybe my wife relies on heavy braking as she had it for the 3 days where it dropped Not sure I can tell her that her driving style costs 10x more brake pads than mine

Would be very interesting if I could drive economically again and it jumped back up to 10K left !!

Unless it can magically remake one of the two stage circuits then it won't...


You are driving from Limerick to Cork.
You have no speedo and no other cars to judge your speed by.
You don't know what time you left Limerick, but you know that on an average day, in average conditions, in an average car, it takes 1hr 40.

You take note of what time you pass through Charleville. You can now roughly estimate what time you will reach Cork based on average conditions.

When you pass the outskirts of Blarney, you know how long it took you to get from Charleville to Blarney. You know how this distance compares to the distance left to Cork so you can know make a much better guess of when exactly you'll get there (based on the same average conditions prevailing for the rest of the trip as the start of the trip).

So if your trip duration to Cork is the lifetime of your brakes, and Charleville and Blarney are Stage 1 and Stage 2 measurement points, how do you get the fox, the chicken, and the bag of corn to the other side of the river if you can only carry two at a time? :pac:;)