How accurate is the idrive info?

Nanu · Post by **Nanu** » Fri Sep 03, 2021 8:10 pm

About 3 months ago the car showed that the rear brakes would need replacing in 3,200 miles.

So booked it in the garage for this Monday to get them done along with the MOT. Since then have done at least 1800 miles and the computer still says the brakes need replacing in 3,200 miles???

ronk · Post by **ronk** » Fri Sep 03, 2021 8:31 pm

I suspect its a finger in the wind!

Silverstar · Post by **Silverstar** » Fri Sep 03, 2021 10:41 pm

In my experience not very. I had the front pads replaced and on resetting the computer, the iDrive showed just 15,000 kms for the new pads which I know just can't be right. A few weeks ago it was showing only a couple of thousand Kms left, but checking the pads there is loads of material still left. Last week I had worn front brake pad warning light pop up and the iDrive showing just 100kms left but the pads still have loads of life in them! I am suspecting maybe the aftermarket brake pad wear sensor is bad? I am not sure, going to take around to the mechanics next week to get it checked.

Jasonn · Post by **Jasonn** » Fri Sep 03, 2021 11:07 pm

I've had exactly the same, all four corners changed in April by my local garage, I've hardly done any real mileage (probably 2-3k and iDrive is pinging up that it needs a service again - no wear so its going back in again

flybobbie · Post by **flybobbie** » Sat Sep 04, 2021 7:44 am

First thing is to make sure when new pads fitted the mileage is reset. Did they actually fit new sensors. They usually brake trying to get them off the old pads.Pads should see something like 45k miles on reset.
3,500 is just guess work, it can just go down to 1,000 over night, if you suddenly did a lot of urban stop start.
Soon as you get low, have them changed.
Personally i have disconnected the brake wear, more hassle than they are worth.

Silverstar · Post by **Silverstar** » Sat Sep 04, 2021 12:41 pm

flybobbie wrote: ↑Sat Sep 04, 2021 7:44 am First thing is to make sure when new pads fitted the mileage is reset. Did they actually fit new sensors. They usually brake trying to get them off the old pads.Pads should see something like 45k miles on reset.
3,500 is just guess work, it can just go down to 1,000 over night, if you suddenly did a lot of urban stop start.
Soon as you get low, have them changed.
Personally i have disconnected the brake wear, more hassle than they are worth.

In my case yes fitted new aftermarket brake sensor cable (ATE brand if I remember correctly). How do you reset the mileage? A few months later when I had the rears changed with the new brake sensor cable, this time the reading is correct and showing around 40,000 or 50,000 before renewal.

enuff_zed · Post by **enuff_zed** » Sat Sep 04, 2021 12:49 pm

Kind of related to this: I got fed up with the amount of brake dust on the back wheels, which I could only attribute to the car using the brakes as part of the DSC.
I tried turning the 'nanny state' off and sure enough, much less brake dust.

I must admit though that after the remap it took me a little while before I went back to switching it off............... and only in the dry now.

Nanu · Post by **Nanu** » Sat Sep 04, 2021 8:16 pm

Thanks guys, helpful as usual.

Will get them replaced seeing it's in the garage for an MOT and I tend to leave the car with my Indy all day and he checks it over for any other issue. The common response appears to be get the brake sensor cable replaced as well as the brakes which I will ask him to do. Hopefully this will be the last garage visit until the oil change in about 8K miles time.

Nanu · Post by **Nanu** » Mon Sep 06, 2021 7:56 pm

MOT passed and new pads and sensors on the rear all for £130.

ihadablackdog · Post by **ihadablackdog** » Mon Sep 06, 2021 9:12 pm

Interesting thread as I'm having the same question....

My rears showed about 1800miles left but it seemed to stay still. Then one day I got a red message saying they needed changing....then the next day, back to 1800?????

Nanu · Post by **Nanu** » Tue Sep 07, 2021 7:53 pm

No tech expert but my Indy said something about a sensor that breaks when the pads get down and the message turns red which means they need doing within about 100 miles. Suspect yours like mine are / were just at that tipping point. New pads and labour was only £90.

Silverstar · Post by **Silverstar** » Fri Sep 10, 2021 4:01 pm

So I took my car into the mechanics today who found the aftermarket sensors cable fitted before had snapped off hence why I was getting the bong! They replaced it with a brand new BMW original cable and reset the computer but it still only shows 10,000 kms for the front pads! Could it be his scan tool? My mechanic says the only option in his computer is to check how much wear is left or to reset it and when he resets it, the car only shows 10,000 kms!

ori · Post by **ori** » Mon Sep 13, 2021 2:57 pm

I always found that reading was way off. Always found beat to measure the pads or wait for the warning to come up when triggered by the sensors.

The strange thing for me was that the rears always wore out quicker than the fronts on my last 2 zeds. I think that has to do with the stability control.

Silverstar · Post by **Silverstar** » Mon Sep 13, 2021 9:57 pm

ori wrote: ↑Mon Sep 13, 2021 2:57 pm The strange thing for me was that the rears always wore out quicker than the fronts on my last 2 zeds. I think that has to do with the stability control.

On most cars the front pads wear out way quicker than the backs but on the Z4 I think it is the other way around. Looking at the history that came with my car the rear pads have been changed twice and fronts once.

ori · Post by **ori** » Mon Sep 13, 2021 10:49 pm

Silverstar wrote: ↑Mon Sep 13, 2021 9:57 pm
ori wrote: ↑Mon Sep 13, 2021 2:57 pm The strange thing for me was that the rears always wore out quicker than the fronts on my last 2 zeds. I think that has to do with the stability control.
On most cars the front pads wear out way quicker than the backs but on the Z4 I think it is the other way around. Looking at the history that came with my car the rear pads have been changed twice and fronts once.

When I spoke to my bmw dealership, it’s quite common on BMWs for rears to wear out quicker. Something about the setup. Who knows?

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