So it happened to me last night after washing the car. Passenger door wouldn't unlock. I managed to sort it by luck in around 10 minutes, after turning the ignition on & off. Here's what turned up:
Address 52: Door Elect, Pass. Labels: 1K0-959-702-MIN3.lbl
Control Module Part Number: 1K0 959 702 M HW: 1K0 959 702 M
Component and/or Version: Tuer-SG 006 1204
Software Coding: 0000692
Work Shop Code: WSC 01279 785 00200
VCID: 3957E53909DF
2 Faults Found:
00097 - Front Passengers Central Locking (Safe) Motor (V162)
012 - Electrical Fault in Circuit
00929 - Locking Module for Central Locking; Front Passenger Side (F221)
008 - Implausible Signal
So I'll be ringing the dealer in the morning. I note that others have found this wasn't covered under their extended warranty; I'll be telling VW to dig into their goodwill pot if it ain't. 29k on an 08 car, I don't expect this sort of thing to happen & cost £300 worth of work.