As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD-SYR - FLT 7316 - DURNIG TAXI, AIRCRAFT RETURNED TO IAD AND MADE AN UNSCHEDULED LANDING DUE TO PRESSURIZATION INTERMITTENT, INOP IN AUTO AND MANUAL. MAINTENANCE REMOVED AND REPLACED CABIN PRESSURE CONTROLLER CHECK VALVE. OPS CHECK OF MANUAL AND AUTO PRESSURE MODES NO DEFECTS NOTED. AIRCRAFT WAS RELEASED AND RETURNED TO SERVICE. (M)