Welcome to the forum,

I'd be tempted to either disconnect the ULF or the battery, It sounds like the phone disconnect signal has somehow hung the ULF.

How did you establish the call (and then dsiconnect)? were you walking away from the car when you disconnected?

__________________
Sept 03, M3, Silver Grey. Retro-fits: Modded Mk4 DVD Drive, OEM Bluetooth, VR Control, Rainbow Speaker Upgrade, Sony SOT Amp, HK Sub, CCFL, Intravee II, NightMode.