As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. SMOKE LAVATORY ENGINE INDICATING AND CREW ALERTING SYSTEM MESSAGE ILLUMINATED DURING DESCENT. AURAL ALARM SOUNDING WITH FLASHING LIGHT AT LAVATORY 4L. NO SMOKE FOUND UPON INSPECTION. SUPPLEMENTAL REPORT: REMOVED AND REPLACED 4F-L LAVATORY SMOKE DETECTOR, PER AMM 26-13-01