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: LEADING EDGE FLAP TRANSIT ILLUMINATED AFTER SELECTION OF FLAPS 1, 4, AND 5; AIRCRAFT ABORTED APPROACH AND RELANDED SAFELY AT ORD. ACCOMPLISHED BITE OF FLAP AND SLAT CONTROL UNIT. FOUND EXT PROX SENSOR EXCESSIVELY DIRTY. CLEANED EXT PROX SENSOR AND ACCOMPLISHED EXTEND AND RETRACT SEVERAL TIMES WITHOUT FAULT. PER AMM 27-80-100, NO FAULTS FOUND.