What was found
IN CRUISE FLIGHT AT FL190 RECEIVED A CABIN PRESSURE WARNING. BLEEDS AERE ON AND NORMAL. COMPLIED WITH CABIN PRESS WARNING CHECKLIST AND DID AN EMERGENCY DESENT. EMERGENCY DECLARED. LANDING UNEVENTFUL. INTERROGATED CDS & FOUND FUALT CODE CPC/OF VALVE DATA FAIL MESSAGE. C/W FIM TASK 21-30-00-810-804 & MCN 621190-2. MCD & AFT CARGO DOOR SEAL INTEGRITY CHECK GGOD IAW AMM TASKS 52-11-31-790-801& 52-31-26-790-801. REMOVED & REPLACED AFT OUTFLOW VALVE IAW AMM TASKS 21-31-16-000-801/400-801. C/W FUNCTIONAL TEST OF THE PRESSURIZATION CONTROL IAW AMM TASK 21-31-00-720-801, OP TEST GOOD, FAULT MESSAGE IN CDS CLEARED & CABIN PRESSURE WARNING DID NOT ILLUMINATE.