On the top cover of the pump there is a control unit (PCU), it has no mechanical communication with an accelerator pedal. The electromagnetic valve of a high pressure
(fig. 207)
opens and closed on TNVD control unit signals. This valve allows to dose out fuel by means of moving of plunzherny pair. Supply of fuel to a nozzle begins at the moment of closing of the electromagnetic valve, and stops at the moment of opening.