As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SELECTED GEAR UP AFTER TAKEOFF AND RECEIVED A GEAR DISAGREE AND A NOSE GEAR DOOR OPEN MESSAGE. RAN QRH AND PROBLEM CORRECTED ITSELF. RETURNED TO DEN. REMOVED AND REPLACED THE NR 3A AC MOTOR PUMP IAW CRJ 200 MM 29-12-03. OPS CHECK GOOD WITH NO DEFECTS NOTED, P/N:848847, S/N OFF: MX677647.