VT Remote Key fail

[Perko78]

Hi! I assumed the battery needed replacing on keys, so had them all replaced, but keys continue to fail -intermittently but very regularly. Took it to auto electrician & he obviously couldn't test for anything until the fault appeared. It seems when the car gets hot- ie, left in sun, that when i return to open the car the computer wont register the signal.
Happens daily, but generally works first thing in the morning. Has anyone else experienced this?

 

[Nut Kracker]

Could be the sensor/ receiver.
It's located at the base of the windscreen, in the middle, between the windscreen air vents.

 

[Perko78]

Could be the sensor/ receiver.
It's located at the base of the windscreen, in the middle, between the windscreen air vents.

Thanks Kracker, will give that a bash!