As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI, FLIGHT CREW NOTED 'SLAT DISAGREE' LIGHT ILLUMINATED WITH FLAPS EXTENDED. FLIGHT CREW ELECTED TO RETURN TO GATE FOR MAINTENANCE. AIRCRAFT RETURNED TO GATE WITHOUT FURTHER INCIDENT. MAINTENANCE PERSONNEL TROUBLESHOT SYSTEM AND IDENTIFIED 'PROXIMITY ELECTRONIC UNIT' FAULTY. UNIT WAS REPLACED. GROUND CHECKS WERE PERFORMED WITH NO FAULTS NOTED. AIRCRAFT RETURNED TO SERVICE. (X)