Diesel maintenance technicians complete service work, replace worn parts and conduct diagnostic tests on heavy-duty equipment and vehicles. In this program, receive classroom and hands-on training in diesel engines, brakes and air systems, drivetrains, preventative maintenance, and electrical and electronic systems. Diesel maintenance technicians complete service work, replace worn parts and conduct diagnostic tests on heavy-duty equipment and vehicles. In this program, receive classroom and hands-on training in diesel engines, brakes and air systems, drivetrains, preventative maintenance, and electrical and electronic systems.