I have found that if there is enough resistance on the locking pins they don't actuate and allow for the mechanism to properly lock. Take the door card off and check if the pin has anything obstructing it. I've seen a worn out rubber grommet that stopped my door locking, replaced that and it's fixed.
Bit of lube doesn't hurt
You can also change the Central Convenience code from 00016 to 00017 with VCDS and when you press to unlock it opens all doors. The trunk button is anyway pretty useless.
Bookmarks