My 2001 Volvo V40 has just developed an odd fault. When I lock it, it appears to do all the right things, but trying the drivers-side door not only opens that door, but appears to unlock the whole car (even the lights come on!)
Any idea what's going on? Is it something I can fix?
I see your post is a few years old but this may help. I noticed my car do this a few times. When you lock the car, check the physical switch inside the car is going down (the one you can pull or push to lock or unlock the car from the inside). Mine gets stuck and does not go down sometimes which I think is a mechanical issue. If I press the lock button on my remote a few times, the switch goes down and the door locks. To fix, you'd probably need to take the interior panel off the door and check the mechanics inside. It may just need a bit of lubrication.