I don't hear any vacuum leaks when the car is locking...
Lately, it's been working sort of okay, but since it's been unreliable, I still have to check if it's locked which is a big pain. Basically, you can hear the locking mechanism trying to lock it and you can see the actual lock struggling to move down, but sometimes it won't go. I'm not sure if there's a vacuum leak because if there is, it should affect all of the doors since it should be all connected to the same motor, right? At least I think that's how it is in my Audi. Anyhow, I'll definitely keep my ears open for a hissing sound to see if it's leaking air.