What was found
(CAN) DURING CRUISE AT 25,000 FT, THE NR 1 POWERPLANT AND NR 1 PEC (PROP ELECTRONIC CONTROLLER) CAUTION LIGHTS ILLUMINATED. THE NR 1 ENGINE WENT INTO THE AMBER. PILOTS CARRIED OUT AN IN-FLIGHT SHUTDOWN, DECLARED AN EMERGENCY AND RETURNED TO BASE. FAULT CODES 161 AND 157 WERE LOGGED IN THE CDS. PROPELLER ELECTRONIC CONTROL UNIT REPLACED, OVERSPEED GOVERNOR (OSG) FAULTS HAVE BEEN SINCE BEEN CLEARED AND FUNCTIONAL CHECKS HAVE BEEN COMPLETED. (TC NR 20070712001)