As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEADING EDGE FLAPS TRANSIT LIGHT CAME ON AT 26000. SLOWED ACFT DOWN TO 230 KTS, EXTENDED FLAPS IAW QRH AND BACK UP LIGHT STILL ON. RETURNED TO DEPARTURE. EMERGENCY WAS DELCARED, LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS GROUNDED. REPLACED S173 LEADING EDGE FLAP EXTEND SENSOR IAW AMM 27-88-11 AND PROXIMITY SENSOR TESTED OK IAW AMM 27-88-11.