Door locks inoperable

I agree. That's what several mechanics have told me. I tried both keyless entery remotes and both keys. The key goes into all 4 locks but will not turn at all. Not sure what to do other than a slim jim. She has been able to get in previously using a key. Did not get cold enough for the locks to have frozen either.

I am not currently home, but first thing this morning I did just that. Both the regular key and spare went all of the way in, but would not turn at all. I tried both keys in all four locks (driver side, front passenger, passenger sliding door and rear lift door). One mechanic suggested frozen locks, but we have had heavy frost in the past and this didn't happen. Cold breeze today, but no precipitation or frost. I am certain they are the right keys due to their shape and size.

The keys actually did allow you to open the glass half of the back hatch. I climbed through, unlocked the doors and popped the hood to jump the battery. The cause of the dead battery was headlights left on. The van started, the remotes worked and still the keys would not turn in any other lock. The battery tested bad (not enough amps) so I replaced it, started the van, hit the unlock on the door and heard a different noise. Tried the keys and they now work in all of the doors and the bottom of the lift gate opens now. A dead battery was the cause, even though I was told a key would override the security system but 3 mechanics, including a Nissan certified mechanic. It has some kind of a deadlock feature built in I guess. The onle change was the car battery. I have not seen this problem or cause any where ion the internet. It is an original, factory installed security system. Maybe ours was just wired differently. I just know to expect to have to climb through the van next time it has a dead battery. I did turn off the headlight delay since the little alarm wasn't enough to alert that they were still on.

Joe