Yellow triangle warning on dash

Hi, I've just had my water pump and thermostats replaced but next day after collecting car I have a yellow warning triangle and message on dash saying 'Put car in P and seek assistance' The car is a 2019 facelift 2 litre petrol DSG with 42k on clock. The temp gauge is at 90 so normal and car drove okay today but now I have this dash warning. Any ideas please. Am I okay to drive it like this. Garage does not know what it might be when I rang them a few hours ago. I'm about an hour's drive away from them atm.