There are so many things that it could be. First thing, figure out when the light is on, then get the car computer scanned for error codes. Without that, anything I say is only a wild guess.
You should figure out why the light is on first because it's on for a reason. Some VW/Audi cars have service reminders that come on to tell you to go to the dealer, your car does not. The light will come back on if you don't figure out why it's on first.
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