As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS PRESSURIZATION FAILED ON SHORT FINAL AT 2500' MSL. SYSTEM RETURNED TO NORMAL AFTER LANDING. MAINTENANCE REPORTS POST FLIGHT REPORT GIVES MESSAGE "21-31 CAB PR LO DIFF PR". NO ASSOC MX MSG. IAW TSM 21-31-00-810-810-A POSSIBLE CAUSE IS ABNORMAL A/C PERFORMANCE DUE TO SUSTAINED RATE OF DESCENT. NO MAINT ACTION NECESSARY. NO 30 DAY HISTORY, AIRCRAFT OK FOR SERVICE.