As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT WOULD NOT PRESSURIZE AFTER TAKE OFF. RETURNED TO BASE AND IT WAS FOUND SAFTEY VALVE WAS OPEN. THE REASON WAS THE SOLENIOD VALVE WAS STUCK IT WAS REMOVED AND CLEANED INSTALLED AND TESTED. GROUND RUNS WERE CONDUCTED AND PRESSURIZATION WAS FUNCTIONAL TESTED AND FOUND SERVICABLE.