Originally Posted by Boss330
There is a BIG difference between a service and a warranty claim. At a service, the info available to the technician will not tell him if there has been a tune present (in the case of a piggyback). If you have had a ECU flash and reflashed back to std. software, all they can see is that at a certain time there was a bunch of fault codes created. If you have a fault code eraser you can avoid that as well.
But, what they look at during a service is just scratching the surface of what the DME have logged. The dealership won't normally have access to read and/or analyze that info however, and in a normal service situation don't need to anyway.
But for a warranty claim involving, say, a engine replacement the dealership will have to turn to BMW HQ for a decision on whether this is a failure covered under warranty or if it's due to driver abuse/non-original software etc. That will be a MUCH more in-depth dive into the DME and engine than they do at a service.
In fact, it would be rather stupid of any manufacturer not to create some sort of logging that will help them decide if someone has tuned their car. Otherwise they would risk having to cover failures that some wonky aftermarket tune might have caused...
I was a shop foreman for a bmw dealer and I've been in the business for awhile. I can tell you that the info they pull From your car Every time they do a "vehicle test" is amazing. Its called FASTA data. It goes to Germany and also BMW NA head quarters everytime the car is scanned. That info goes in a folder for your VIN and they use it for quality purposes and or to back a warranty refusal. Some of the info cant be used against you technically in a court of law. They wont tell you that unless you bark back.