As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AROUND 3K FEET ON FINAL APPROACH CABIN ALTITUDE STUCK AT 3000 AND WOULD NOT DESEND. SUDDENLY THE PRESSURIZATION STARTED A 1000/MIN RATE OF DESCENT TO FIELD ELEVATION. CONT. FROM PREVIOUS SIDE. CABIN AUTO CONTROLLER IN POSITION AUTO. ACCOMPLISHED BITE OF AUTOMATIC CABIN PRESSURE CONTROLLERS IAW MM 21-31-00 NO FAULTS NOTED.