Error codes when giving the car serious welly with traction and stability control fully switched

[Pbondar]

To plagiarise the Hitchhikers Guide to the Galaxy:

Pbondar: What happens if I press this button?
Busterboo: I wouldn't-
Pbondar: Oh.
Busterboo: What happened?
Pbondar: A sign lit up, saying 'Please do not press this button again.'

Yes....I think it’s to do with my Ukrainian ancestry...

I’m sure it must have been my cousins who were operating Chernobyl and pondered the question...I wonder what that button does?

[Smartbear]

ED5BA989-C045-4E90-9B7D-687BC0BB532C.jpeg (45.83 KiB) Viewed 492 times

Rob

[Pbondar]

Very good

To turn back to the original point...the premise is..if you switch off ALL the traction control aids and stability control via the traction switch is everything fully disabled?

Judging by the error codes, which don’t appear under simple full throttle acceleration, then it looks like the DSC unit is still intervening in some ways..

I assume it’s this rather than the marginal extra torque beyond the nominal limit of the box 457nm vs 450nm..

There has been a lot of discussion of this on other forums..with amongst other points that on certain M cars the US version of ‘nanny control’ is more aggressive than the European versions which have more relaxed ‘nanny control’

[enuff_zed]

I'm sure I've read several times that BMW will always leave a little bit of 'nanny' even when you think you've switched it all off.
Which makes you only a driving semi-god

[MACK]

Could this all be down to the gearbox not liking the torque being put through it with your mods? Iirc you havent had the box software remapped and you must be pushing the factory standard limits.

[Busterboo]

How many times in the last 79,120 kilometres has Monsieur Clouseau's 'Yellow Peril' been driven like this, I wonder?

Exploring the performance limits of such cars often throws up spurious faults, doesn't it?

(Having re-read this, I've realised it's just a polite version of john-e89's previous post. )

It’s a valid point...it’s the only time I’ve tried it...

In all seriousness, it seems probable.

A couple of months ago, I overheard a good BMW indy telling a worried customer just what I've said above. (You see, my post was really 'I don't know, but I know a man who does.')

[Pbondar]

Could this all be down to the gearbox not liking the torque being put through it with your mods? Iirc you havent had the box software remapped and you must be pushing the factory standard limits.

Hi there..I can't see any form of sensor spotting the difference between 450nm and 456nm (and we're not sure how the factory's nm is vs the tuner nm)..

The ZF 8 HP box as it is back throttles the engine to 380nm on 3rd and 6th gears anyway..

I would assume a 450nm limit would like the 380nm limit be done 'softly' via engine shut down?

Reading further, it would appear (without further programming) that the e diff function remains on and even with traction off still intervening..the e diff breaking the spinning wheel..the system uses wheel revolution count and throttle position to determine 'rear brake overheat' not an actual sensor...so maybe by the 3rd attempt the ecus had declared rear brake overheat and shut things down as part of the usual 'it is verboten' approach to excessive behaviour?

[Pbondar]

How many times in the last 79,120 kilometres has Monsieur Clouseau's 'Yellow Peril' been driven like this, I wonder?

Exploring the performance limits of such cars often throws up spurious faults, doesn't it?

(Having re-read this, I've realised it's just a polite version of john-e89's previous post. )

It’s a valid point...it’s the only time I’ve tried it...

In all seriousness, it seems probable.

A couple of months ago, I overheard a good BMW indy telling a worried customer just what I've said above. (You see, my post was really 'I don't know, but I know a man who does.')

Spoke to local garage man this morning who has a long trade history in Merc/Porsche/Audi and he said the same thing..with almost all cars now, especially the more powerful ones you never fully disabled the safety systems to stop people kiling themselves..

If the problem doesn't re-appear after shutdown and restart then its probably last ditch attempts to stop you either killing yourself and/or destroying the car..

[R.E92]

I think it's more likely caused by the car no longer fitting the model after fitting the LSD.

The stability control system has diagnostic built in for sensor plausibility. My feeling is that with the LSD fitted you are altering the physical behaviour of the rear axle. The wheels speed sensors and the shaft speed sensor in the transmission will have a modelled relationship based on an open diff.

There's a decent amount of tolerance built into these diagnostics so that's probably why you won't see it flag up all the time and only when really pushing the car. The same kind of thing happens when people alter the rolling radius of their wheels, changes like that just eat into the tolerance before intervention like individual wheel braking and engine power reduction is used.

[Pbondar]

I think it's more likely caused by the car no longer fitting the model after fitting the LSD.

The stability control system has diagnostic built in for sensor plausibility. My feeling is that with the LSD fitted you are altering the physical behaviour of the rear axle. The wheels speed sensors and the shaft speed sensor in the transmission will have a modelled relationship based on an open diff.

There's a decent amount of tolerance built into these diagnostics so that's probably why you won't see it flag up all the time and only when really pushing the car. The same kind of thing happens when people alter the rolling radius of their wheels, changes like that just eat into the tolerance before intervention like individual wheel braking and engine power reduction is used.

Hello, thanks for the hypothesis..as I think has been much discussed no one outside ATE/BMW knows the coding logic and what the individual parameters do..apart from by experimentation..

Its more clever/complex than I imagined..but being out of tinkering with cars for a long time, the full computerisation of cars never ceases to amaze me..

I may just get the e-diff coded out..although under normal use it all seems ok..I'll fit the 35is rear brakes and calipers shortly and run it for a while to see what effects if any that has on brake balance etc..

In reality I'm not into 'drifting' my car under normal circumstances so playing with those parameters would be a waste of time..

As discussed it was a deliberate 'what will it do if' and clearly got upset..not something I would normally do..

Thank you for your input..

As an aside, using either ProTool or ISTA etc can you code out the speed limiter at the top end?

[R.E92]

Speed limiter removal requires a change in the DME so you'd need to visit the tuner again. Most places remove the limiter by default.

[Pbondar]

Speed limiter removal requires a change in the DME so you'd need to visit the tuner again. Most places remove the limiter by default.

Thanks!