Turbocharger (TC) Wastegate Regulating Valve Solenoid
The TC wastegate regulating valve solenoid allows the PCM to indirectly control the turbocharger wastegates. The TC wastegate regulating valve solenoid controls the feedback pressure to a pneumatically powered wastegate diaphragm in order to control the boost pressure limit. When the compressor outlet pressure is allowed to increase, a pneumatically powered actuator opens each turbocharger wastegate and limits compressor outlet pressure.
The TC wastegate regulating valve solenoid supplies pressure to the pneumatically powered wastegate diaphragm, which regulates the maximum boost pressure to a constant value. A pressure greater than 35.5 kPa (5 psi) on the pneumatically powered wastegate diaphragm opens the wastegate. The TC wastegate regulating valve solenoid can partially vent (reduce) the control pressure, resulting in increased regulated maximum boost.
A duty cycle of 100% vents feedback pressure to the intake air supply, eliminating any boost limit control by the wastegate. A duty cycle of 0% results in the base boost limit.