As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLT FLT 1576 EN ROUTE FLL TO CLT. THE LEFT ENGINE WENT TO IDLE THRUST IN FLIGHT. THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE PERFORMED AN ELECTICAL CHECK ON THE J4 HARNESS AND WIRING. NO FAULTS WERE FOUND. MAINTENANCE REPLACED THE LEFT ENGINE J4 HARNESS AND LEFT ENGINE ECU AS A PRECAUTION.