assuming that your unit is really an ULF (you did say that it has purple FAKRA connector for the BT antenna), in the facelifted cars there is no button in the center console anymore... the pairing is happening from the talking head button on the steering wheel - you turn the ignition on, press the talking head, hold until the nav screen shows the BT pairing words, put your phone into search mode, it finds the ULF, you let it pair, it asks for the code, you give it a code, it pairs, than asks if you want to connect to the ULF automatically from that point on...

Easier said then done!!! I have tried this procedure couple of dozen of times, was able to pull it off only once... finally, i got fed up with this, pulled out the INPA, connected to the BT unit, and told it to pair - and voila! it paired... granted, not everyone has INPA to do this, in this case, you just have to hope that you can catch that elusive moment from turning the ignition and pressing the talking head... i suspect, that the BT unit should be "just" awaken for this to happen, as if the BT is already awaken on the first unsuccessful attempt, the following attempts will not yield a good result... i realize that the formal instructions claim that the BT unit is in pairing mode for the first 2 minutes and no talking head needs to be pressed... but it means, that everytime i start the car, the BT module is in pairing mode, looking for a new mate... i do not see flashing LEDs next to the nav screen...

just find the INPA, be done with it...