Check The Doors For Lock/Unlock And Open/Close Operations.

Using the key, lock and unlock the door several times to check for normal operation. Open and close the door several times for smooth movement.

Fig 1: Checking Door Lock/Unlock Operations
Courtesy of SUBARU OF AMERICA, INC.
Close the driver's door completely, and place the door lock knob (A) to the lock position. Then pull inside door handles (B) to ensure that doors will not open.
For other doors, place the door lock knob (A) to the lock positions and then pull the inside door handles to ensure that the doors will not open.

Fig 2: Identifying Door Lock Knob And Inside Door Handles
Courtesy of SUBARU OF AMERICA, INC.