Anyone Know What This Maintenance Reminder Is For?
 

Sup Guys,

Anyone know what this maintenance reminder is for?

http://i48.photobucket.com/albums/f2...psvowh1gky.jpg

Transmission if you have over 100k.

I'm at 64k. Does it mean the fluids need to be changed?

Did you buy it new or used?

All BMW fluids are "lifetime" :nanana: ,so must be something else.

I wasnt aware that the CBS had ANY service indicator at ANY mileage


OP did you put all 64k on yourself? Any chance the mileage isnt accurate?

Just a guess: it's calling for oil change in the transfer case, which does have a countdown timer... But given the stated mileage, either someone messed with the case, or the odometer.

No, it was a recent purchase. I cant say if the mileage was tampered with. Nothing seemed out of order on the carfax.

btw, did my picture get deleted? Am i not able to post pictures? Im new here.:(

Picture fine. you on a phone?

Do you know what a tamper dot is? Anyone read your DME during the pre purchase inspection?

Maybe a low fluid condition via a sensor?
Just a WAG...
GL, mD

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.

JCL- figured this would catch your eye...

I dont think we know really WHAT is being measured by the BMW capactive 'oil quality' sensor. Metal? Viscosity? A combination? I will bet money that it cannot, however, measure 'additive package'. but thats not the topic here.

The odd thing is that I cannot recall ANYONE posting a CBS warning to change transfer case oil, ever....

:thumbup:

http://cdn.meme.am/instances/250x250/56504947.jpg

You asked for it

Off topic slightly
 

There have been one or two warnings posted. I think they were all X3 models. No iDrive warning, in that case, but the rest is the same. Not many get the warning because of tendencies to change fluids early and often, over and above manufacturer's recommendations. That's a joke, BTW.

I think we do know what the engine oil sensor is measuring. I think the technical papers from the sensor developer were posted, and I recall an SAE paper. I remember reading them years back. Capacitance, in combination with the integrated fluid temperature measurement in the sensor, correlates to degradation of the oil. They are measuring oxidation directly, soot in some cases, water in some cases, and additive depletion (the technical phrase used by several different manufacturers of these sensors). I would suggest that the additive depletion is related to TBN, or alkalinity. That would be an indirect measure of additive depletion. As additives are depleted, the TBN drops from the starting point. The computer is calculating the relative drop, and using a map to check if it is in the expected range. If you go to a good oil sampling lab, they will use starting TBN and measured TBN to evaluate oil condition and report on the need to change it, instead of focusing on the trace elements which are commonly referenced, and which refer to engine wear rates instead of oil condition.

You can't measure contaminants without things like mass spectrometers. One sensor manufacturer refers to contaminants, but I think they mean glycol or water. Maybe soot. Particle counters are available, but not rugged enough for mobile applications IMO. And I don't know of anyone using a similar sensor for viscosity measurements.

Edit: my research was a few years back. The link provided in the post above is BMW info but relates to the Continental sensor. I did have the Continental tech paper at some point, and it discussed additive depletion. I went to find the Continental sensor paper as a link, and found this following summary. It seems there are viscosity sensors now. And additive depletion is mentioned as a correlated output from a system using a di-electric capacitance sensor, which is the technology Continental supplies to BMW. Another sensor is listed as monitoring additive condition by relating dispersed soot to undispersed soot, a function of the soot dispersion additives and how many of them are left. Ard, you owe me a beer some day. ;)

Determining Proper Oil and Filter Change Intervals: Can Onboard Automotive Sensors Help?


Jeff

Just a quick update but first i want to say thank you for being so informative. I appreciate relying on my brothers on the forum for help.

I went to an indy BMW Specialist earlier today. Without mentioning what I heard previously from the BMW Service Center, the mechanic checked the CBS and quickly confirmed, the oil needed to be changed in the transfer case. He mentioned its a routine maintenance. The vehicle generally alerts the driver when its time to change the oil. He quoted be $80 labor plus the oil.

We are in general agreement...

My point is that there is a bunch of hand waving going on with many of these lay press pieces, as well as 'trust us, we are omnipotent' from the mfg... and my specific point with quoting JCL was that none of the sensors measre "depletion of the additive package".

Note that I am not saying the capacitance they measure and the ways in which they filter and reduce these measurements are useless, nor am I saying they do not correlate with oil life. They most likely do. We just do know know the correlations or errors or foibles.

We have water, soot and fuel contamination...as well as changes in viscosity...and changing wear metals... does the sensor measure one of these? some of these? or is it simply a correlation wherein multiple aspects combine in non-linear ways, but by testing a correlation has been developed to allow that to say "this oil is probably bad"?

From continental:


I suppose that somewhere, behind a large NDA, you can find UOAs with correlated long term sensor readings- curves, frequency spectra, etc, etc...


But we dont have it here.


We meet up, Im buying beers for both of you.

While we are at it- same article, different sensor:






Sounds a bit different than the BMW.continental sensor.

Say, I wonder if there IS some method to BMWs madness that ONLY BMW oil be used...so the sensor has a known baseline? :cool:

Oil properties may affect accuracy of the algorithms, but he designer would have to accommodate different types of oils. It does highlight the importance of resetting the service indicator when the oil is changed so the system knows to take a starting point sample for the baseline.

Back to the original topic, this is also why it would be important to reset the adaptations when changing the transfer case fluid, even if the flag hasn't been tripped for oil degradation. While the sensing technology is different, it seems reasonable to me to let the system function as designed.

Correct!When i had the "Transfer case oil replacement due" message on my 530xit I tried to erase it,but it was coming back after a few miles drive.Pretty sure the control module goes into some kind of safe or low-torque mode and it will not start the adaptation process unless reset.

you are corret JCL, you must reset the adaptation after an oil change.

What is an adaption reset and how do I do it?

Can you PM me with the name and location for your indy BMW Specialist? I live in Fairfield County, CT. Thanks!!