My car was booked into Audi today for coolant loss which apparently turned out to be an air lock from previous repair but when they phoned to report the car was ready for collection they said my car showed a T code which means it's been chipped and warranty was void? the only thing that's happened between it's last visit to Audi and this one is I've bought an OBD11 and turned off start stop, the guy said they would investigate further to cause of the above code but now I'm concerned as I'm about to extend the warranty for another year.