As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT, AT APPROX 4000' CABIN RATE INCREASED TO 1500 FPM DECENT. CABIN RATE MATCHED ACFT AUTO DESCENT RATE, AUTO COULD NOT KEEP UP WITH CABIN DECENT RATE. COULD NOT PRESSURIZE ACFT ON CLIMB OUT. PERFORMED AOM 1 PROCEDURE & RETURNED. R & R MANUAL CONTROLLER IAW AMM 21-31-02. OPS CHECKED GOOD.