As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE CREW REPORTED THAT WHEN SELECTING CLIMB THRUST, THE THRUST RATING MODULE ASSEMBLY WENT TO TAKEOFF RESERVE MODE. THE CREW WAS UNABLE TO CHANGE THRUST RATING MODE AND RETURNED TO MKE, LANDING WITHOUT INCIDENT. MAINTENANCE FOUND THE THRUST RATING MODULE ASSEMBLY TO BE FAULTY. MAINTENANCE REPLACED THE THRUST PANEL MODULE ASSEMBLY. OPERATIONAL CHECKS OF THE THRUST RATING MODULE ASSEMBLY WERE GOOD WITH NO FURTHER DEFECTS NOTED.