What was found
AT FL 350 RECEIVED ECAM CAB/PR EXCESS CAB ALT MASTER WARNING ECAM, SHOWING SYSTEM 2 AMBER ON LOWER ECAM THAT WOULD NOT STOP WITH THE WARNING. THE AIRCRAFT WAS GROUNDED. REPLACED CPC 1 AND 2 IAW AMM 21-31-34 AND OUTFLOW VALVE IAW AMM 21-31-51. PERFORMED AN OPS CHECK OF CPC 1 & 2 IAW AMM 21-31-00-710-002-A, AND 21-31-00-710-003-A. OPS CHECKED THE OUTFLOW VALVE IAW AMM 21-31-00-710-002-A, AND 21-31-00-710-003-A. TESTED OK, NO FAULTS NOTED. AIRCRAFT OK FOR SERVICE.