Door Lock Inhibit
WARNING: This page is about a different car, the 2004 Dodge Intrepid, 2004 Chrysler Intrepid, 2004 Chrysler Concorde, and 2004 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
With the key in the ignition switch and the driver's door open, the Body Control Module (BCM) will ignore the command to lock the power door locks.
Once the key is removed, or the driver's door is closed, the BCM will allow the power door locks to lock.