What was found
AIRCRAFT REJECTED TAKEOFF AT 70 KNOTS DUE TO RIGHT EICAS MESSAGE MASTER CAUTION AND ENGINE CONTROL LIGHT TURNED ON. THE FLIGHT CREW PERFORMED THE QRH 7.14 PROCEDURE, CONFIRMING THE FAILURE. MAINTENANCE PERSONNEL PERFORM THE FIM 73-06 TASK 801 PROCEDURE, DETECTING THE RIGHT ENGINE HMU DAMAGED. AIRCRAFT WAS SENT TO THE HANGAR AND THE RIGHT HMU WAS REPLACED IAW AMM 73-21-10, TESTED CORRECT. THE HIGH ENERGY STOP INSPECTION WAS NOT NECESSARY DUE TO THE MAXIMUM GROSS WEIGHT 79 015 KG AND BRAKES ON SPEED 110 KNOTS WERE NOT EXCEEDED IAW MM 05-51-07.