When enabled by the Machine ECM, the Motor ECM (3) monitors and controls the operation of the six power transistors (three pair) of the Control No. 2 section of the power inverter.
When the key start switch is turned ON, the Generator and Motor ECMs perform system checks to determine the status of the power transistors. If there are no faults in the power transistor, the Generator and Motor ECMs communicate with the Machine ECM and then begin controlling the operation of the Control No. 1 and Control No. 2 sides of the power inverter.