As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT 2452, ON CLIMB-OUT FROM SJC, MASTER WARNING AND THE FUSELAGE DOOR WARNING LIGHT ILLUMINATED ON MFD. AFT PASSENGER DOOR SHOWED OPEN, FA CONFIRMED VISUALLY DOOR WAS CLOSED AND PRESSURIZATION WAS NORMAL PER CHECKLIST. MAINTENANCE FOUND AFT PASSENGER DOOR PROX SWITCH SLIDING BRACKET FULL OF ICE AND H2O. CLEANED AND LUBED BRACKET. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.