As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAIN GEAR DOOR CYCLED SEVERAL TIMES AFTER TAKEOFF. AFTER ACCELERATING THROUGH ABOUT 200 KTS IT DIDNT CYCLE ANYMORE. FOUND LEFT LGDRCL PROXIMITY SENSOR OUT OF LIMITS. ADJUSTED LEFT PROXIMITY SENSOR LGDRCL IAW Q400 AMM TASK 32-61-00-280-801 TR-32-492. LEFT LGDRCL PROXIMITY SENSOR IS WITHIN LIMITS. WITH HYDRAULICS APPLIED LEFT LANDING GEAR DOOR AFT OPENS AND CLOSES NORMALLY. NO FURTHER DEFECTS NOTED.