As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF LANDING GEAR HANDLE WOULD NOT ALLOW UP SELECTION, LANDING GEAR WOW SYSTEM FAIL MESSAGE APPEARED. EMERGENCY DECLARED AND RETURNED TO DEPARTURE. FLIGHT LANDED WITHOUT INCIDENT. MESSAGE CLEARED AFTER SEVERAL MINUTES. ACCOMPLISHED JOB CARD 43L71132002 AND PERFORMED SUCCESSFUL GEAR EXTENSION AND RETRACTION IAW AMM 32-33-00. THE AIRCRAFT WAS GROUNDED.