As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 2340. AFTER TAKEOFF RECEIVED A FUSELAGE DOOR WARNING FOR THE MAIN CABIN DOOR. THE FLIGHT ATTENDANT REPORTED THAT THE DOOR APPEARED NORMAL, AIRCRAFT PRESSURIZATION WAS NOT AFFECTED. RETURNED TO THE FIELD AND ACCOMPLISHED A UNEVENTFUL LANDING. MAINTENANCE REPLACED THE DOOR PROX SENSOR. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.