Dealer Diagnostics

Not sure this is specific to my Karoq, but probably other models as well 🤔

The dealer ran diagnostics on my car and satisfied themselves that they had identified the problem and provided the solution. Unfortunately, this was not the case and it has to go back again for a replacement part.

My question then is whether they automatically clear codes on the machine, or if this is operator choice, since clearly the faults returned within 5 miles of leaving the dealer! Thanks.