As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CABIN PRESSURIZATION FLOW LIGHT CAME ON AT FL310. CABIN CLIMBING AT 100 FEET PER MINUTE BEGAN DESCENT TO 8,000 FEET. CABIN FLOW LIGHT OFF AND ON INTERMITTENTLY. EXECUTED RAPID DESCENT TO 8,000 FEET. DURING THIS EVENT LEFT DUCT PRESSURE WAS AT 20 P.S.I. AND RIGHT AT 20 P.S.I. MAINTENANCE ACTION INVOLVED REPLACING BOTH PRESSURE CONTROLLERS. CHECKED SERVICEABLE.