What was found
LOSS CONTROL OF AUTOMATIC PRESSURIZATION CLIMBING THRU 40,000 FEET, ASSOCIATE CAS MESSAGES, CABIN CLIMB TO 10,800 FEET. PAX MASK'S DIDN'T DROP. ON DESCENT MANUAL PRESSURIZATION APPEARED TO BE INOPERATIVE. POWERED ACFT & FOUND OUTFLOW VALVE WOULD NOT MOVE IN AUTO AND WAS SLOW IN MANUAL MODE. SLAVED IN ANOTHER CABIN PRESSURE TRANSDUCER AND FOUND NO FURTHER DEFECTS AT THIS TIME. RETURNED ACFT TO ORIGINAL CONFIGURATION REMOVED TRANSDUCER. INSTALLED A DIFFERENT TRANSDUCER IAW CMP261244. COMPLIED WITH PRESSURIZATION DELTA P FUNCTIONAL IAW CMP 213056. NO FURTHER DEFECTS NOTED.