Hello, I have a 2005 Audi A6 Avant with factory fitted Kessy / Keyless system. The system has never quite worked reliably (I purchased the car second hand). Problem: Doors: I have to be very patient to open the doors (and sometimes doesn't work or I'm not patient enough). Same goes for locking the doors with the black rubber button on the handles. Engine start/stop: Sometimes never works (or inpatient) and sometimes I get "no key identified" and other times it just works. However, I notice that if I have managed to start the engine with Kessy I can always Stop engine with Kessy. Further information: VCDS: I have scanned the car and have no fault codes. Weather: I have noticed that now it is cold Dec the system has started to work much much better. Observations: While cold weather and system seems much better I can open and lock easily well from all doors (and start/stop engine from within car). Battery: Is brand new, original Audi and coded to the car. Software: Audi Specialists checked and there were no software updates for my car for this system. What could be the problem? The Kessy unit? Antennas? Anything else? I am very puzzled as to what this could be so would be grateful for advice as handing it over to Audi blindfolded is just not an option as too expensive. Any advice from your experience would be MUCH appreciated. PS: I have read the Kessy unit sometimes need refurbishment as two Mosfets on the board get tired with age but not sure if the symptoms of my car fit this approach?