Turbocharger (TC) Wastegate Regulating Solenoid Valve
The TC wastegate regulating solenoid valve allows the powertrain control module (PCM) to indirectly control the turbocharger wastegates. The TC wastegate regulating solenoid valve 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 solenoid valve 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 solenoid valve 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.