What was found
FLT 4429 DURING TAKE OFF CREW REPORTED A LANDING GEAR AIR/GROUND FAIL CAUTION MESSAGE ON ECIAS. MESSAGE WENT OUT, THEN CAME BACK ON AS THEY CONTIUED CLIMB. DECLARED AN EMERGENCY & LANDED WITHOUT INCIDENT. MESSAGE STAYED ON THROUGHTOUT FLT & LANDING. ACFT REMOVED FROM SERVICE. PERFORMED VISUAL INSPECTION OF LT NLG PROXIMITY SWITCHES 1 & 2 & RT MLG SWITCHES 1 & 2. NO DEFECTS NOTED. PERFORMED PROXIMITY SWITCH FUNCTIONAL CHECK IAW AMM 32-63-05, R & R RT MLG SWITCH NR 2 IAW AMM 32-63-01. PERFORMED AIR/GROUND WOW OPS CHECK IAW AMM 32-63-00. OPS CHECK GOOD, NO DEFECTS NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.