What was found
B-18609 ATB DUE TO OUTFLOW VLV CAN'T CONTROL. AT FL370 CABIN ALT CONTINUED TO CLIMB 500 FT PER MIN, EMER DESCENT INITIATED. CABIN ALT WARNING HORN & LIGHT ON. GND BITE FOUND FAULT CODE 007 ON CPCS. IAW AMM 21-31-03 REPLACED OUTFLOW VLV & CHECKED AUTO & MANUAL FUNCTION STILL HAS, AUTO FAIL, LIGHT ON. BUT MANUAL MODE TESTED OK IAW AMM 21-31-00. CPCS BITE PROCEDURE FOUND FAULT CODE 001 IAW FIM 21-31 TASK 804. WIRING CHECKED NORMAL. FOUND DETAIL MSG SHOW, CPC-PNL WIRING, ON CPC 1 & 2, THEN REPLACED CPC 1 & 2 & CABIN PRESS CONTROL MODULE IAW AMM 21-31-01 & AMM 21-31-02. 5. IAW AMM 21-31-00 PRESSURIZATION SYS GND TESTED OK & MANUAL MODE CONTROL ON MODULE TEST OK. IAW AMM 05-51-91 PERFORM CABIN PRESS LEAKING CHECK WITHIN LIMITATION. RII CONTROL NR 16-006. AMM & FIM REVISION R59. REMOVED PARTS INFORMATION, OUTFLOW VLV, PN 4063-19972-01AA, SN 9510512. CPC 1, PN 7121-19971-01AC, SN 0412090. CPC-2, PN 7121-19971-01AC, SN 9960399. CABIN PRESS CONTROL MODULE, PN 7123-19973-02AB, SN 97031118.