As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AIR INTERRUPTED INTO SMF ACCOUNT PRESSURIZATION ISSUE.ON CLIMBOUT ONLY 1 DIFFERENTIAL PRESSURE. OUTFLOW VALVE NOT FULLY CLOSED. LEVELED OFF AT 13,000 THEN CABIN ALTITUDE REACHED 10,000. WARNING SOUNDED. O2 UTILIZED. APU BLEED AIR ADDED. NO EFFECT AT 7,000. EMERGENCY DECLARED. OPERATIONAL CHECK OF OUTFLOW VALVE IAW AMM 21-31-00, OPS CHK NORMAL. ALSO PERFORMED A/C PRESSURIZATION LEAK CHK IAW AMM 05-51-91. NO LEAKS FOUND. SYSTEM OPERATES NORMALLY.