What was found
CREW MANUALLY SHUTDOWN (IFSD) LT ENGINE DUE TO A PEC FAULT & POWERPLANT MESSAGE FOLLOWED BY PROP OVERSPEED. AT FL 9500, TORQUE WAS INDICATING 106 PERCENT, POWER WAS THEN REDUCED AND WITH MCL SET AT 850, RPM WENT TO 1064. THE FAULT CODES RETRIEVED AFTER THE ACFT LANDED SAFELY WERE AS FOLLOW: CH A: 236, 907 CH B: 158, 907, 260 FAULT CODE 158 COULD INDICATE A MALFUNCTION OF EITHER LOCAL PCU, PEC, &/OR OSG PITCH CONTROL UNIT (PCU) REPLACED.