As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5173 - PASSENGER DOOR LATCH CAUTION MESSAGE CAME ON AFTER TAKEOFF. RETURNED TO AIRPORT AND LANDED WITHOUT INCIDENT. INSPECTED PAX DOOR HANDLE, WIRING AND SWITCHES NO DEFECTS FOUND. PERFORMED PRESSURIZATION CHECK AND COULD NOT DUPLICATE MESSAGE.