As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRESSURIZATION OVER PRESSURIZING AT 18,000 FEET. CABIN ALTITUDE READS +250 FEET AND 8.4 DIFFERENTIAL. ON DECK WITH DOOR OPEN CABIN PRESSURE READS 600 FEET. REFERENCE DAYJET WORK ORDER 1299, NRI 2. REMOVED AND REPLACED PRIMARY OUTFLOW VALVE IAW EA500 AMM 21-30-12. PERFORMED CPCS OUTFLOW VALVE ADJUSTMENT/TEST IAW EA500 AMM 21-30-01. OPS CHECK GOOD. PERFORMED PRIMARY AND SECONDARY OUTFLOW VALVE DELTA-P LIMITER TEST IAW EA500 AMM 21-30-03. OPS CHECK GOOD.