I have a 1998 Buick Skylark, things were working fine, then I got a second key cut just in case I ever lost mine or locked it in the car. I drove with it a couple of times, then went back to my original key. About a week later, the anti-theft light started coming on and now the car stalls sometimes when I start it. Anybody know what might cause this?
Also, I will add that my remote keyless entry and remote trunk went about the same time. When I am driving, as soon as I put it in drive, the doors all lock, as normal, but when I stop and turn the key off, the door all unlock expect for the driver door, whic remains locked.
I have seen this problem before, What it is the connection tabs that are in side the lock cylinder the rear the key are starting to go bad. They send a small amount of power threw the chip in the key and the computer knows how many ohms the key should have so it knows it has the right key, When this connection start going bad and they lose there connection the computer thinks it has the wrong key and will shut off the engine. The new you had made(being new and not warn) may have moved the connectors in the lock cylinder just enough to give you problems. To fix the problem you will have to have to key readers replaced inside the lock cylinder.
As for your drivers door not unlocking it cold mean the power door lock motor is starting to go bad and it will have to be replaced. I have a car that does the same thing, sometimes I have to hit the unlock button more then one to get the drivers door to unlock.