on board computer service accuracy

[mr.tourette]

So whilst changing my wheels last week I noted the rear brake pads seemed a bit on the thin side, probably a bit of life in them I thought so checked the on board servicing system, says they have 11000 miles left in them. Just how reliable do we think this system is as by my eye I would usually be looking to change them when they looked like they do now, I'm not one for wearing them close to the bone ?

[Jasonn]

I don't trust them at all - if it looks wrong I'd do them, same as the oil service, I'd rather change it before the computer tells me it's knackered.

My wife's X3 said the pads needed changing soon after they'd been replaced (the new wear sensor was defective - could just as easily been wrong the other way)

Computers are great, but no substitute for routinely checking things yourself

[Pbondar]

The condition based servicing system has a whole set of algorithms it uses to determine when items should be checked..

The brake pads part is probably one of the most limiting as the inputs, mileage, time, number of brake applications are offset against unknown variables like type and condition of brakes n pads plus how heavy footed the driver is...

In part that’s why there is a brake pad sensor as a fail safe to capture an impending issue..

IMHO CBS is ok to protect the uneducated/ uncaring / not bothered from gross errors that wil damage the car / themselves during the warranty period..

A structured time and distance based serving regime is much better, but less cost effective if short term ownership is your focus..

[mr.tourette]

Thought as much..new pads it is

[Nictrix]

Is the brake sensor attached?
I have seen a warning before on our old mini saying the pads only had 1000 miles left and on inspection there was over half the pad material left.
The system seems to be geared towards people not looking for themselves and just heading to a dealer who will swap them out £££

[Pbondar]

Is the brake sensor attached?
I have seen a warning before on our old mini saying the pads only had 1000 miles left and on inspection there was over half the pad material left.
The system seems to be geared towards people not looking for themselves and just heading to a dealer who will swap them out £££

I think on E89s if the brake pad wear sensor is disconnected you will get No warnings at all..

[Nictrix]

Is the brake sensor attached?
I have seen a warning before on our old mini saying the pads only had 1000 miles left and on inspection there was over half the pad material left.
The system seems to be geared towards people not looking for themselves and just heading to a dealer who will swap them out £££

I think on E89s if the brake pad wear sensor is disconnected you will get No warnings at all..

Sorry by not attached I meant connected to the pad. This would mean that the car thinks its connected but it never wears down.

[mr.tourette]

didn't look that closely at the wear sensor and tbh its the first time I've looked at the computer servicing thing, its the kind of thing I would just look at and decide when to do it. The pads are by no means on the metal, there is probably 3 maybe 4mm of material left but as I said thats usually the point i would think of changing rather than trying to eke out the maximum life from them

[Pbondar]

Another calculation is that normally the CBS makes sure it gives you a warning / leaves enough residual to get to the planned service interval..

I think (for most forum members) once they aquire their cars they tend to get 'over serviced'..not that is a bad thing!

[Silverstar]

Shortly before my front pads went the car was showing 15,000km of life left in them one day and then the next day that dropped to 800 or 500kms!

Not sure how it went from 15k to under 1k overnight but sure enough the pads were at the end of their life. The computer is now showing the rears at 1900kms, having physically checked them it seems about accurate. Pads already purchased just waiting for the imminent.

Oddly after I changed the fronts the computer reset but still showing just 15,000 Kms I was expecting on new pads it to say around 30 to 40K. Who knows how this thing works.

[mr.tourette]

Shortly before my front pads went the car was showing 15,000km of life left in them one day and then the next day that dropped to 800 or 500kms!

Not sure how it went from 15k to under 1k overnight but sure enough the pads were at the end of their life. The computer is now showing the rears at 1900kms, having physically checked them it seems about accurate. Pads already purchased just waiting for the imminent.

Oddly after I changed the fronts the computer reset but still showing just 15,000 Kms I was expecting on new pads it to say around 30 to 40K. Who knows how this thing works.

Yeah my fronts are showing 37000, from service history they were done around 5000 miles back

[lewis1962]

Not a techie at all, but did do my rear pads myself, £30 instead of £200 quoted by the dealer.

It does make me laugh on youtube when they say changing your brakes is easy, it is, if you have a ramp !

I was in agony for days after kneeling down taking 2 wheels on and off ! Must be my age...

I did notice that when removing the sensor that a part of it broke off, I was hoping to reuse it as the warning light hadn't come on.

I ordered another and will fit it when I next feel up to it !