As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT AT FL 360, THE PRESSURIZATION AUTO FAIL LIGHT ILLUMINATED. BOTH BLEEDS AND PACKS ON. CABIN DESCENDED 1200 FPM. SELECTED ALT MODE. CABIN STABILIZED AT FL 230. AIRCRAFT DIVERTED. COMPLETED QRH GOING TO MANUAL MODE ON APPROACH. MAINTENANCE FOUND BOTH CABIN PRESSURE CONTROLLERS BITE TEST FAULT FOR THE CABIN OUTFLOW VALVE. REPLACED THE OUTFLOW VALVE IAW AMM 21-31-03-000-801. OPS CHECKED NORMAL, AIRCRAFT RETURNED TO SERVICE.