What was found
(CAN) T/O ABORTED DUE TO "POWERPLANT" MESSAGE ON ED. AFTER TAXING OFF THE RUNWAY AND RT POWER LEVER IN DISC, PROP OSG TEST IN PROG AND ABORT APPEARS UNCOMMANDED. ENGINE RUN PERFORMED, OSG TEST PERFORMED SUCCESSFULLY BUT WHEN POWER LEVER GOES FROM FLIGHT IDLE BACK TO DISC SAME PROBLEM HAPPENS AGAIN AND POWERPLANT MESSAGE COMES ON AGAIN. A NEW PCU INSTALLED ON NR 2 ENG. PERFORMED OPERATIONAL TEST. AIRCRAFT RETURNED TO SERVICE.