As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW REPORTED THAT AFTER TAKEOFF, THE NOSE GEAR DOORS DID NOT CLOSE POST GEAR RETRACTION. THE GEAR WAS CYCLED IAW CREW QRH AND EXPERIENCED THE SAME RESULT. CREW OPTED TO SELECT GEAR DOWN, DUE TO ICING CONDITIONS, THE FLIGHT DIVERTED. MAINTENANCE ACTION RESULTED IN THE MECHANICAL SEQUENCE VALVE BEING REPLACED.