Hi all.
I know this has been covered before, but I thought I would share my experience of my Premium Audio Unit on a 2006 Discovery LR3 HSE stuck in phone mode.
Firstly, the problem arose after a blocked sunroof drain tube on the drivers side (right in UK). The tube was blocked by the rubber block behind the air intake. (This is where the drain tube exits in to the inner panel) All I did to unblock it was remove the rubber block and discard and flick the end of the tube a few times and all the water ran out... job done. Due to this blockage the water had back filled in to the headlining, dripping from the overhead centre light fitting, and the water had travelled down the drivers side, 'A' pillar lining pooling in the foot well. First thing to do is clear the blockage to prevent any further water ingress and let the interior totally dry out.
I then removed the centre surround, and unscrewed the audio unit. (Unscrew climate control below first to allow audio unit to slide out)
Turn off ignition, and disconnect rear fibre optic MOST cable. (Left connector) Turn ignition on and check display shows AUX or CD or FM etc. Make contact with MOST connection and check display and listen for any sound/interference over speakers. If display still shows Phone Mode, disconnect MOST cable and check display. Press and hold AUX. AUX should remain on display. Put aux lead in rear passenger compartment and connect ipod or phone and play music. Reconnect MOST and turn ignition back on. It should now be up and running. If not, try a combination again of ignition off and MOST connect and disconnect, with AUX or Radio buttons pressed.
I know it sounds a bit hit and miss but it worked for me... and I'm so so relieved.... especially as Land Rover said they have never fixed a vehicle with this fault!!