Hi All,
I had this issue last year lucky for me I had my car under the extended warranty so booked it in, they advised me there is a junction box on the drivers side A-pillar which had gone faulty, this aparently there are two types of these juctions boxes so make sure they order the correct one for your car as my dealer ordered the wrong first time around and had to order the correct one, and the part comes from Japan so you got to wait roughly a month, if your lucky in can come in 2 weeks depends on customs i guess.
Hope this helps