As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SDL/IND - WHILE EN ROUTE AFTER CLIMB-OUT TO 40,000 FEET MSL, FLIGHT CREW NOTICED CABIN PRESSURIZATION CLIMBING. FLIGHT CREW MADE A PRECAUTIONARY EMERGENCY DESCENT AND DIVERTED TO GUP. MAINTENANCE REMOVED AND REPLACED BLEED AIR REGULATING VALVES. AIRCRAFT RETURNED TO SERIVCE.