As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT RETURNED TO FIELD WHEN DURING CLIMB, THE CREW RECEIVED A PASSENGER DOOR WARNING. MAINTENANCE INSPECTED THE AC AND FOUND THE PROXIMITY SENSOR OUT OF ADJUSTMENT. THE SENSOR WAS ADJUSTED AND THE OPERATIONAL CHECKS WERE GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.