Help needed! Passenger side doors won't unlock.

[Lianneed]

Hi all,

3 days ago I purchased a 2008 Audi A3, 5 door. All of the doors, boot and fuel flap have seemed to work okay and locked/unlocked using the fob.

Then yesterday afternoon, both the front and rear doors on the passenger side stopped working. They lock with no problems, but won't unlock with the central locking. There's a quiet noise coming from the doors, as though they are trying to do something, but they won't budge. When we open them from inside, they unlock straight away. They then stay unlocked and can be opened as normal from outside, until the car is locked down again. Tried unlocking with the key in the drivers door, doesn't make any difference. Both doors on the drivers side work as they should, 1 fob click to open drivers door and a second click opens the back. No lights on the dash and in interior lights work as normal.

I've searched the web and found people who have had problems like this with 1 door, but nothing about 2 doors on the same side packing in at the same time.

We've got lots of history on it, a local business rep had it and did mostly motorway miles on her own. Thought that maybe the passenger side doors haven't been used much for a few years. Could that be something to do with it?

It's a dealership part ex, that we had from our local car auction, so sold as seen.

Any advice appreciated. TIA