could be any number of things, you can't know what tripped it until you have it looked at by a dealer or someone else who can use a VAG-COM diagnostic tool to pull the fault code.
flashing check engine light = drive to the dealer or have it towed there right away
steady on CEL = okay to drive but get it checked out soon to be safe.
flashing check engine light = drive to the dealer or have it towed there right away
steady on CEL = okay to drive but get it checked out soon to be safe.