As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON CLIMBING THROUGH 4000 FT THE PASSENGER DOOR LATCH CAUTION MESSAGE ILLUMINATED, FOLLOWED BY A PASSENGER DOOR WARNING MESSAGE. FOLLOWED QRH. RETURNED TO GTF. INSPECTED DOOR AND CHECKED CABIN PRESSURE. DOOR AND PRESSURE CHECKS OK PER MM 21-31-00.