As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LEFT ENGINE UNCOMMANDED ACCELERATION AND N1 RED, WITH INDICATION WELL ABOVE 100 PERCENT DURING CLIMBOUT FROM CLT. ALL OTHER LEFT ENGINE INDICATIONS WERE TRACKING HIGHER PRIOR TO THRUST REDUCTION. CREW FOLLOWED QRH, RETURNED TO CLT AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT, REMOVED AND REPLACED LEFT ENGINE BROWN W9 HARNESS (FOUND CHAFED) AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT WAS RELEASED FOR SERVICE.