b'technicians in the workshop are not trusted to replace or rework individual components, but because the turbo- Structure / Design chargerandtheelectromechanicalactuatormustbe precisely matched to each other before installation in theof the HELLAvehicle. This calibration is carried out in the dismantledTurbocharger Actuatorstate on a low bench for turbochargers. On this special test bench, the vehicle-speciic low rate (MIN/MAX low)1) Upper housing coveris determined and set as part of a basic adjustment. For2) Printed circuit boardthis purpose, depending on the model, it may be neces-sary for some actuators, prior to calibration, to be irst3) Worm gearactivated using a special map so that they can then be4) Sealrecognized in the vehicle by the engine control unit. 5) Retaining bracket for motorAlthough many turbocharger actuators look the same on6) Electric motorthe outside, their design and coniguration can differ as7) Gearbox housingregardsperformanceandalignmentdependingonthe8) Fastening element / levervehicle type and the turbocharger unit. In their respec- 9) Brackettive combinations with the turbocharger and in accor-dancewithvehiclemanufacturerrequirements,two10) Shafttypes of HELLA turbocharger actuators can be installed.11) Drive segmentAdistinctionismadeherebetweenthe"Smart"and12) Rotor"Simple" versions. Thanks to an integrated control unit, the "Smart" autonomously regulates the adjustment of theguidevanes,whilethe"Simple"iscontrolledbya higher-levelenginecontrolunit.Althoughsimilarin appearance, the technical design of the electronics, of theA defect in the gearbox of the turbocharger actuator is gearbox and of the housing coniguration is fundamental- usually preceded by a defect in the guide vane adjust-ly different. ment on the turbocharger. Over time, the exhaust gas lowcreatesheavycontaminationinsidetheturbo-Therefore repair work involving the exchange of variouscharger. Such soot formation impairs the functioning of components,suchasgearsorelectronics,takenfromthe guide vanes. This leads to a higher torque require-different actuators is not possible. ment for the entire actuator and ultimately to gearbox damage at the actuator and error entry in the engine control unit.HELLA offers extensive and further train-ing opportunities. More information available at: www.hella.com/techworld/us/22'