The TEC controls almost everything about a small APU turbine engine from start to shut down. After pressing the start button, the TEC will run the engine autonomously at a constant speed independent of the load until the operator commands a shutdown. It performs fuel control mainly through an electrical fuel pump but will control another low-pressure fuel pump as well as a fuel shut-off valve. It further features ignition and load control.
The TEC monitors engine speed, exhaust gas temperature, fuel pressure, oil pressure and oil temperature for engine control and can provide operational gauges of these in a variety of ways.