Unugga cabbiraadda shidaalka ee Bosch (valve metering valve) oo ay soo saartay YS waa mid ka mid ah qaybaha ugu muhiimsan nidaamka sahayda shidaalka naaftada. Waxay xakameysaa qadarka shidaalka soo galaya xadiidka shidaalka si ay u buuxiso shuruudaha dejinta cadaadiska ee nidaamka tareenada caadiga ah. waxay sameeyaan xakamaynta wareegga xiran ee cadaadiska tareenka iyo dareenka cadaadiska tareenka.
Soo gaabinta Ingriiska ee Bosch shidaalka ee ay soo saartay YS waa ZME, MEUN, nidaamka Delphi waxaa loo yaqaan IMV valve, nidaamka Denso waxaa loo yaqaan SCV valve ama PCV valve.