As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CABIN ALTITUDE CLIMBED DURING DESCENT WITH LOW ENGINE POWER SELECTED. CABIN ALTITUDE WARNING (CABIN PRESS) LIGHT ILLUMINATED AND CREW USED FIXED OXYGEN SYSTEM UNTIL CABIN ALTITUDE WAS RESTORED. OPERATIONAL CHECK OF ENGINE HP VALVES CARRIED OUT IAW AMM 21-00-00 UNABLE TO FAULT. BOTH LT AND RT ENGINE 55 PSI BLEED AIR PRESSURE SWITCHES REPLACED AND SYSTEM TEST CARRIED OUT. AIRCRAFT SERVICEABLE, NO FURTHER DEFECTS EVIDENT. PRESSURE SWITCHES OUT OF TOLERANCE SUSPECTED TO BE CAUSING DEFECT.