As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF A LAV SMOKE INDICATION APPEARED ON EICAS. NO VISUAL SMOKE WAS NOTED. RETURNED TO THE FIELD. INSPECTED LAVATORY SMOKE DETECTOR AND PERFORMED SMOKE DETECTOR TEST IAW EMB 145 AMM 26-15-00. PERFORMED TAKEOFF POWER GROUND ENGINE RUNS. NO DEFECTS NOTED.