As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT PASSING 3000FT. AVIONICS SMOKE ECAM ANNUCIATED SMOKE NOT CONFIRMED BY SNIFFER FAN. MADE PRECAUTIONARY RETURN TO DEPARTURE, EMERGENCY DECLARED. ON GROUND FOUND NO SMOKE EVIDENT BY ODOR. PERFORMED TROUBLESHOOTING IAW FIM 26-15-00. REMOVED & REPLACED SMOKE SENSOR IAW AMM 26-15-12 . PERFORMED TEST OF SMOKE DETECTION IAW AMM 26-15-001 AND NO DEFECTS FOUND. SYSTEM TESTED OK. ACFT OK TO CONTINUE.