As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK, CLIMBING THROUGH 19,000' CABIN ALTITUDE WARNING HORN AND LIGHT CAME ON. RIGHT RAM AIR DOOR FULL OPEN LIGHT WAS ILLUMINATED FULL BRIGHT. CABIN WAS CLIMBING THROUGH 10,000' AND REACHED A MAX OF 13,000'. MANUAL CONTROLLER STOPPED THE CLIMB (MAYBE WE WERE DESCENDING AT THE SAME TIME). / R&R PRESSURE RELIEF VALVE IAW MM.