What was found
CABIN ALTITUDE AMBER EICAS MSG CAME ON AS WE CLIMBED THRU 12,000 FT CABIN ALTITUDE SHOWED 9000 FEET 1.4 DIFFERENTIAL AND RATE OF CLIMB OF 1000 FEET. LEVELED AT 14000 FEET AND SELECTED FULL HOT ON PAC TEMP SEL RATE OF CLIMB WENT TO ZERO AND CABIN STAYED AT 9000 UNTIL WE DESCENED THRU 9000 AT GEAR DOWN THERE WAS A PRESSURE SPIKE AND THE CABIN FOLLOWED THE PLANE ALTITUDE AND RATE OF DESCENT. REMOVED & REPLACED CABIN PRESSURIZATION CONTROLLER IAW CITATION 750 AMM 21-31-00. SELF TEST SATISFACTORY.