What was found
(CAN) TORQUE FLUCTUATIONS/IFSD DURING FLIGHT AT 1000 FT ALTITUDE THE ENGINE PARAMETER INDICATIONS BEGAN TO FLUCTUATE. THE PILOT TRIED MANUAL MODE AND THE BEEP SWITCH TO NO AVAIL. AFTER A FEW SECONDS THE CAS MESSAGE "ELECTRONIC ENGINE CONTROL FAIL" APPEARED. THE PILOT ELECTED TO SHUTDOWN THE ENGINE AND RETURN TO BASE, WHERE AN UNEVENTFUL SINGLE ENGINE LANDING WAS ACCOMPLISHED. TROUBLESHOOTING IS ON-GOING AND FOCUSING ON A POSSIBLE INDICATION PROBLEM CAUSED BY A FAULTY T5 HARNESS.