Tampering dot is gone with E39,E46 and E53.The system is a bit more complicated now,definitely not possible for amateurs to do a rollback.

So i checked into my local BMW service station in Port Chester NY just to get an idea of what it might be. The person behind the service counter stated the VTG oil needs to be replaced in the transfer case.

Not quite sure what that is. Ive never had that done before. He quoted me about $150 labor plus the oil. Parts had the oil for $25 a quart.

He mentioned the service notification can go on at 60k, 100k or when needed.

I have code only for the VTG(transfer case) oil condition in my '06 530xit,but it had 170 k miles.
A sensor measures the resistance of the oil in the transfer case.More parts wear inside,more metal pieces in the oil,resistance decreases.At a predetermined point a code is set.

That's the first time I hear such a thing: what's your source?

This is not true: most are, not all.

The TC oil is definitely not lifetime and albeit some SA claim otherwise, the owner's manual states the transmission fluid (at least for the ZF-6HP, don't know about the 8 speed) is 100K miles. The brakes have a fluid which is also not lifetime.

Also incorrect: the E70 has a manipulation dot that appears between the trip and the odometer (IIRC). It works the same way it has always done which is comparing the odometer recorded in the instrument cluster with the one store in the CAS.

PS: not trying to be a dick here since I'm sure you're trying to help, just correcting inaccuracies that do nothing more than a dis-service...

Obviously I know nothing about BMW,mostly pretending that have some knowledge,or 20 years experience with BMWs.

From Pelican parts:

" The transfer case fluid condition is monitored by the transfer case control module. In theory, you will be notified when a service is due on the info display via the transfer case control module. "

BMW E90 Transfer Case Fluid Replacement | E91, E92, E93 | Pelican Parts DIY Maintenance Article

No need to engage in reductio ad absurdum: I never said you knew nothing. Actually I find your posts very informative. It just happened that in this post you made definitive statements on a couple of things which turned out to be inaccurate and I thought it was helpful to point them out.

We all learn from experience, but sometime the First Law of Clarke gets in the way...

Now back on the subject at hand: I was not questioning the fact that the VTG control module monitors oil status. I was questioning the fact that it uses "a sensor measures the resistance of the oil in the transfer case.More parts wear inside,more metal pieces in the oil,resistance decreases."

I've never heard of such sensor, for sure the ATC 700 in my 35d and the ATC 400 in my X3 don't have it and they simply monitored oil indirectly by tracking use and extrapolating the remaining useful life of the oil. Given the very limited gears in the transfer case the primary contaminant of oil comes from the wear of the clutch plates.

The link you posted doesn't mention it nor does any of the BMW literature I have; perhaps you read it elsewhere (hopefully not a forum post ;))

Perhaps this will help.

So we are agreed that the alert is for the transfer case. Yes, it is condition based monitoring, but not via a sensor in the oil. That is the engine oil condition sensor, and it measures capacitance, not resistance. It isn't picking up metal particles in the fluid, but rather the depletion of the additive package.

The transfer case fluid condition is not based just on mileage, like the oil change interval was based on fuel consumed. It is based on changing frictional characteristics of the gear oil, and the control box recognizing that those characteristics are crossing a threshold, measured by comparing slip characteristics (input and output speeds) and clutch engagement pressures (actuator torque).

I don't have a quote from the manuals on this iPad, but here is a quote from a BMW tech with an extract from the manual which covers it. Sorry I had to use a forum post but it does include the extract from the technical literature.

http://www.xoutpost.com/881911-post7.html

Edit: there are likely differences between the various x-drive transfer cases as to the above details. I know the procedure changed relating to resetting the TC adaptations at some point.

Ok,let's start from the beginning.I actually like your write-up for the diesel CCV oil separator and i planned to make something similar.It actually becomes necessity with the tune I am developing with some overseas partners.

The same way I am mistaken,you may be too.So the correct term would be "statements that I believe are inaccurate"

I am quite mistaken in that case and I have no idea how that idea got into my head :( I believe the oil quality in the VTG is monitored by the VTG control unit by terms of clutch pack slipping,but do not quote me on that.

There are some clues in this post that it is kind of irony.Regardless of the intended fluid life,you will not get this message on the dash,even for the engine oil change.

First of all,there is a huge misunderstanding how the tampering dot works on the older models.The mileage from the cluster is stored in the light module and the EWS.If you set the mileage to 0 in the LM or EWS it will take the value from the cluster first time the car accelerates to ~30 mph.If you lower the value in the cluster and the values in the LM and EWS are higher the tampering dot will illuminate.Same will happen if you change any of those modules and the VIN numbers dont match,regardless that the mileage may be accurate.
In the newer generation BMWs the mileage is stored in the cluster and CAS actively,+many other modules but only passive.If you lower the mileage in the cluster and install it on the car it will take the mileage from CAS,no tampering dot will appear.Vice versa is valid too.If you install a different cluster ,or different CAS and VINs do not match,the tampering dot may appear.But many other functions will not work and the car will be a mess.I have never seen the dot illuminate on any of the new models,and after deep google research this is the only thread I found that mentions the tampering dot:
http://www.xoutpost.com/bmw-sav-foru...-dot-came.html
But it is not very definitive after all.So yeah,the truth is out there ;)
Sorry for the long post,at least we keep the forum alive and kicking.