A key is necessary to release the tang.
How does door lock works.
The lock mechanism may not work simply because the lock is dirty or dry and needs to be lubricated with graphite do not use any type of oil because this will gum up the works.
If the door lock relay needs to be replaced it can be indicative of an underlying concern with the power door locks.
Once the key is removed the spring will automatically push the latch back out.
The key to match the particular lock lifts the pins to the correct height to allow the latch the part that protrudes into the door frame to be pulled back against the spring allowing the door to open.
How door locks work.
The key turns the cylinder which in turn turns something called a cam.
An improperly functioning latch may be the result of a poorly fitting door.
The lock is set from inside the door.
The cam then releases a spring which shoots the tang forward securing the door to the wall.