What was found
DURING CLIMBOUT, CABIN PRESS MASTER WARNING ILLUMINATED. MAINTAINED 17,000' AND RAN PRESSURIZATION FAIL CHECKLIST. INITIALLY I WAS UNABLE TO CONTROL PRESSURIZATION MANUALLY BUT A FEW MINUTES LATER, MANUAL PRESSURIZATION WORKED. DURING INITIAL CLIMBOUT BELOW 10,000' WE NOTICED ALMOST NO AIR COMING OUT OF THE VENTS AND AIR WAS REALLY COLD EVEN WITH TEMP KNOBS TURNED MOST OF THE WAY UP. DIVERTED TO PDX MANUALLY CONTROLLING PRESSURIZATION, NO FURTHER ISSUES. RETURNED TO FIELD. REMOVED FROM SERVICE. INTERROGATED CDS FOR F.C. FOUND NO CABIN PRESSURE CONTROL F.C. FOUND ECS CODE 3102, REF FIM TASK 21-60-00-810-811. R & R ABSOLUTE PRESSURE SENSOR, REF Q400 AMM TASK 21-52-06-000-801 & 21-52-06-400-801. PERFORMED OPERATIONAL CHECK OF ECS, REF Q400 AMM TASK 21-61-00-710-802. OPERATIONS CHECK GOOD AND NO FAULTS NOTED. PERFORMED FUNCTIONAL TEST OF PRESSURIZATION CONTROL, REF Q400 AMM TASK 21-31-00-720-801. NO PRESSURIZATION FAULT CODES WERE NOTED. UNABLE TO DUPLICATE PRESSURIZATION DISCREPANCY. AIRCRAFT RETURNED TO SERVICE.