What was found
EN-ROUTE, AT ROTATION, LT ENG OVERHEATED. CLIMBING OUT HAD TO REDUCE POWER TO STAY OUT OF RED, 744 DEGREES MOMENTARY. LT ENG STAYED AT IDLE POSITION. DECLARED AN EMER, THE FLIGHT RETURNED TO FIELD & LANDED WITHOUT FURTHER INCIDENT. RETRIEVED EXCEEDANCE ON EXCEEDANCE PAGE. ACFT TRIGGERED A START LIMIT EGT ON TAKEOFF. MAX EGT ON TAKEOFF WAS 744 DEGREES, FOR 27 SECONDS. FOR EGT LIMIT WITH N3 ABOVE 50% IS 850 DEGREES BEFORE ENTERING INTO ZONE A. CONTACTED, & SENT DATA TO ENGINEERING. OCCURRENCE WAS DUE TO A SOFTWARE ISSUE IN EICAS COMPUTER. ALL PARAMETERS WERE IN LIMITS.