This is strange to me but maybe one of you have run into this before. I only have one key and no fob. If I lock the car and then try to unlock it with the key in the driver side door it will not unlock or respond at all. I can turn the key to lock and it will cycle the lock again but nothing when I try unlocking. I can walk around to the passenger side door and put the key in and it will unlock all doors including the driver door. Funny thing is the key works to lock and unlock the driver door as long as the door is open. Close the door and I have to unlock from the passenger side door.

 

Although not a part of your post, but please make sure you have 2 master keys. If you have one master key, please register the 2nd key. If you loose the only master key, you will face major difficulty. For further reading please read through the sticky threads.

The door lock is a combination of mechanical and electromechanical. Once the key allows the cylinder to turn, it activates the electromechanical function with the ecu [lowering/raising windows, lock unlock all doors etc].

To isolate the problem take these steps.

Lower all windows [just in case]
Disconnect the battery. [you will loose settings]
Now test the mechanical portion of the key lock.

Salim