Hi i own a Vauxhall Astra Design on a 2007 plate and today when it was quite cold i started the engine and the board information display read 17 Celsius I knew this was wrong as it is quite cold so as I was driving along it sorted itself out and I thought that was that. However later on I went back to my car I unlocked it and a letter F came on the screen where the outside temp is normally displayed this lasted for about 20 seconds then all was fine however I went to a Vauxhall specialist who guessed it was a fault with the outside temp sensor and what do you know he felt around for it and saw that it was loose and dislodged so he very kindly put it right and all was fine I then thanked him and was on my way however when I went back to my car what do you know the F came on again for about 20 seconds then all was fine. My question is does anyone know what is causing this and how can I sort it. I have been told it may be just the temp sensor that needs sorting as the car is running great with no EML coming on etc and that if it is the temp sensor the car will still drive well. I shall look forward to your replies.
Since then i have had a new Temp sensor fitted and the F still comes up however it only comes up when the car has been stationary for a while (parked up and locked) and when i go to unlock the doors then after 20 seconds or so the temp goes back to normal and all is fine

Kind Regards