As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT DIVERTED TO PIT ON ACCOUNT OF AUTO PRESSURIZATION FAILURE, FOLLOWED SHORTLY AFTER BY LOSS OF MANUAL PRESSURIZATION CONTROL. MAINTENANCE REMOVED AND REPLACED OUTFLOW VALVE IAW AMM 21-31-51. OPS CHECK SYS 1 & 2 IN AUTO AND MAN MODES, NO FAULTS NOTED.