Hi all just bought my first golf gti and loving it however the central locking will only open all doors but not lock the doors and boot can I get advice please.
I had similar problems, there's a myriad solutions. My problem was that all the doors except the front passenger side would lock and unlock on the fob. The front passenger side worked intermittently and then locked fast. I could neither unlock it nor lock it. I eventually managed to unlock it by getting in the car, switching the ignition on and then using the button on the driver's door control panel to unlock it. Once I'd one this I squirted liberal quantities of WD40 into the lock mechanism on all four doors and they've worked perfectly ever since. The bootlid was a different matter. This wouldn't lock at all, it was permanently open and the lock mechanism was jammed solid. However, once again liberal quantities of WD40 in the lock and lots of key wiggling eventually freed the lock off, but I can now only lock and unlock it using the key, not the fob. I can only think that in this case the lock motor is burned out. All that said, it the lock mechanisms are good it's possible that the soldered joints on the control cards in each door are borked and will need remaking. If you're handy with a soldering iron it's not a difficult job if a bit fiddly and time consuming.
Def could be cracked solder on the pins & sometimes the rubbers on the micro switches deteriate or rip off causing ingress of dirt n crap.
I recently had a problem with the rear passenger lock not opening, when remote pressed all the other doors n boot were fine but you have to press fob once to open jus the drivers door but twice for all doors n boot this is a safety feature for when your on your own.anyway as the rear passenger door would not unlock i had to open it from the insid3 handle n it worked fine after that so i think that the mechanisms get stuck sometimes n a manual opening can regenerate the lock .im gona have mine off soon so i can check it proply n wd40 the thing lol
Sounds like a duff door lock module Dose the puddle light on any of the doors stay on ? Aftermarket stereo's can interfere with the locking as well