I was wondering if anyone knows how to chang the central locking on a 1997 VW Golf GTI - 5 door hatch.

At present when I open the car using the key(no remote at present) all the doors are unlocked. However in the users manual it says that this can be changed to just opening the drivers door with one turn of the key and the rest of the car with another turn of the key.

It was in for a service the other day and I asked them to change it while there but this did not happen and I was wondering if anyone knew how to do this or is it best that a VW service center does it.

I know the system runs using a vacumm pump in the boot so I am not sure how hard it would be to change myself.

Thanks for any help.