As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED TO IAD DUE TO LEADING EDGE SLAT INDICATION. *S/D* INDICATION WAS CAUSED BY FLAP SLAT ELECTRONIC UNIT BALL FAULTING M548 OUTBOARD SLAT ROTARY VARIABLE DIFFERENTIAL TRANSFORMER. REPLACED M548 ROTARY VARIABLE DIFFERENTIAL TRANSFORMER PER MM 27-81-11. FLAP OPERATIONS CHECK NORMAL AND FINAL FSEU BITE CHECKS WERE NORMAL.