As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4557, CREW REPORTED THAT AFTER TAKEOFF LANDING GEAR AIR/GND FAIL CAUTION MESSAGE ILLUMINATED. RETURNED FOR NORMAL LANDING. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED LGEU IAW EMB 135 32-32-01. PERFORMED OPERATIONAL CHECK NO DEFECTS OR MESSAGES NOTED. PERFORMED FCF, NO DEFECTS OR MESSAGES NOTED. AIRCRAFT RETURNED TO SERVICE.