This bulletin applies to all 2012-2021 Audi models. The customer may note that the warning light is on with low coolant level or a coolant leak is found under the vehicle front.
The pressure relief valve in the filler cap of the cooling system can give the impression that the valve malfunctions. Coolant marks around the filler cap or the coolant expansion tank do not necessarily indicate that the cap is malfunctioning. Check the filler cap, according to Elsa. If the filler cap passes the test, do not replace the cap. Continue fault finding.