As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED #2 ENGINE TORQUE BEGAN FLUCTUATING +/- 10-15%. WHEN #2 ECU WAS SELECTED OFF THE CONDITION STABILIZED BRIEFLY THEN #1 ENGINE TORQUE BEGAN FLUCTUATING +/- 5-10%. AIRCRAFT RETURNED TO DCA. MAINTENANCE FOUND THE #1 ENGINE ECU FLAGGED ON THE ENGINE CONDITION PANEL. REPLACED THE #1 ECU.