As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEPARTING, ON CLIMB OUT. AFT CARGO DOOR WARNING INDICATION AND AUTO PRESSURIZATION INOP. AIR RETURN. MAINTENANCE FOUND THE AFT CARGO DOOR PROX SWITCH STUCK IN THE UP POSITION. MAINTENANCE CLEANED AND LUBED THE FLOATING PROX SWITCH. VERIFIED ON PSEU THAT THE FAULT WAS THE ABDLK PROX SWITCH TO FAR WHICH RENDERED THE AUTO PRESSURIZATION CONTROLLER INOP. PERFORMED CHECK ON AUTO PRESS CONTROLLER AND AFT BAGGAGE DOOR. OPPS CHECKED GOOD AND RETURNED TO SERVICE.