As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT THE LANDING GEAR LEVER COULD NOT BE MOVED UP AFTER TAKEOFF. ALSO GOT LANDING GEAR AIR/GROUND FAIL MESSAGE ON ICAS. CREW DIVERTED TO EWR AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED SYSTEM. CLEANED CONNECTIONS ON NOSE LANDING GEAR PROXIMITY SENSORS, AND CYCLED GEAR SEVERAL TIMES. SYSTEM OPERATIONALLY TESTED GOOD. AIRCRAFT RETURNED TO SERVICE.