As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) - DURING TAKEOFF ROLL PILOT NOTICED THE LT RPM STUCK AT 2000 RPM 'MOMENTARILY'. ALL OTHER ENGINE PARAMETERS NORMAL. CREW PROCEEDED TO BASE WITH NO PROBLEMS. TROUBLESHOOTING FOUND DIFFERENTIAL CONTROLLER AT FAULT. UNIT REPLACED WITH OVERHAUL AND AIRCRAFT RETURNED TO SERVICE. FAULTY UNIT RETURNED TO OVERHAUL SHOP AND STRIP REPORT REPAIR.