As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: AFTER TAKEOFF LEFT TRAILING EDGE FLAP INDICATOR SHOWING SLIGHTLY GREATER THAN THE UP POSITION; CYCLED FLAPS BACK TO 1 THEN UP STILL SHOWED THE SLIGHT ASYMMETRY ON THE INDICATOR. AIRCRAFT AIR INTERRUPTED BACK TO AND LANDED SAFELY AT JFK. FOUND LEFT FLAP POSITION TRANSMITTER OUT OF RANGE. REPLACED LEFT FLAP POSITION TRANSMITTER. PER MM 27-58-01. ACCOMPLISHED OPS CHECKS, ALL OPS CHECKS GOOD.