As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIGITAL READ OUT LIGHT FOR OUTFLOW VALVE INOPERATIVE. UNABLE TO READ POSITION OF OUTFLOW VALVE. ACFT GROUNDED. VERIFIED INDICATOR IS INTERMITTENT. REPLACED CABIN PRESSURE CONTROL MODULE. ALL OPS NORMAL, IAW AMM 21-31-02. GROUND VERIFICATION SATISFACTORY.