As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN PRESSURE CWP MASTER WARNING ON. NO CONTROL IN MANUAL MODE, UNABLE TO CONTROL PRESS, WOULD NOT OPERATE IN AUTO AND WOULD ONLY WORK INTERMITTENTLY IN MANUAL. AIR RETURN TO DTW. MAINTENANCE FOUND PAX DOOR SEAL BLOWN OUT. REMOVED AND REPLACED PAX DOOR SEAL IAW SF340 AMM CH 52-10-15-4. LEAK CHECK GOOD. PERFORMED AUTO AND MANUAL PRESSURIZATION CHECKS, ALL CHECKS GOOD.