Common Rail Piezo-injector Functions: extension of the actor module (piezo-layers) movement of the coupler module opening of the valve piston in the switching valve actuation of the nozzle needle and injection description ordernumber 476 see also: common-rail injector II injection-nozzle holder with hole-type nozzle and pintle-type nozzle high-pressure fuel pump TSI (FSI) vane-pump