I’ve got a 2021 40 TFSI, and the key has a new battery, but occasionally doesn’t open the doors. I open the car by removing the cover over the drivers door handle and open manually using the key in the lock.The alarm then goes off but by placing the key on the pad under the armrest it resets and then works ok for a while. Then for no reason repeats this fault again and this is becoming more common. 

Have you tried the spare key as that can help rule out if it's a faulty key.  

Hi Steve,

Many thanks for your reply unfortunately I was sold the car with only one key. Perhaps I now need to investigate buying another one?

regards

Mike 

Possibly. Alternatively you could get a diagnostic check to see if any fault codes flag up. This will b e cheaper than a new key. 

Thanks again Steve, I’ll try it and post how I get on. In the meantime I’m keeping the key separately from my mobile phone as I’ve read on another thread that this can affect the key from working. 🤞

Please do. Oh I've never heard that before. That's certainly an interesting theory.