As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CARGO DOOR CAUTION MESSAGE AND OPEN INDICATION DURING CLIMB OUT. RETURN TO FIELD. VERIFIED DOOR CLOSED AND SECURED ON ARRIVAL. OPENED DOOR AND OPERATED THE SWITCHES SEVERAL TIMES. APPLIED CONTACT CLEANER TO SWITCHED. OPERATED DOOR SEVERAL TIMES. NO FAULT NOTED. OK FOR SERVICE.