As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALTITUDE SELECTOR KNOB ON THE PRESSURIZATION PANEL WHEN TURNED DOESN'T CHANGE OR SELECTS A RANDOM NUMBER TO OPPOSITE DIRECTION. ACFT GROUNDED. VERIFIED FLT ALT KNOB STICKS OR WORKS BACKWARD WHEN OPERATED. REMOVED AND REPLACED CABIN PRESSURE CONTROL MODULE IAW AMM 21-31-02. ALL TESTS PASSED. NO FAULTS AFTER REPLACEMENT.