[Westlake]

Good afternoon iam having problems with my I 30 Hyundai 2010 the passenger rear door won’t open .if I mass around with the inside door lock it some works with the key for a few days after that it won’t open again I’ve tried spraying the lock with normfest high pressure ultra some times if iam luck it will work for a few days then stop .any one else had the same problem.

[Aye30]

Yes, I sprayed teflon cable lubricant into the bowden cables, and it worked flawlessly, then 2 weeks later the battery wouldn't start the car.  The battery was on its way out, and the first symptom was the most used passenger door. It would fail to unlock in the morning, but would unlock when when the engine was running and pushing the unlock button on the drivers door. Does manual manipulation of the door lock feel stiffer than the other side? Also some people have been on this site in the past asking how to get the door card off when they cannot open the door.  It  involves cutting holes in the card, so repair at the earliest convenience. 

[BrendanP]

If the lock stops working and the door is locked shut, cutting holes in the door card doesn't help. The lock mechanism is screwed to the edge of the door and the inner steel door panel conceals it, even with the door card removed. If the door lock is intermittent, fix it ASAP while the lock still opens. At the very least, take the door card off and unplug the electrical wiring to the lock. That will disable the central locking and deadlock, but at least you can use the door levers inside to manually lock/unlock the door whilst you find a replacement lock assembly.