Circuit/System Description

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

The turbochargers each incorporate a vacuum operated wastegate that is controlled by the engine control module (ECM) by means of remotely mounted solenoids, to regulate the pressure ratio of the compressors. The wastegate valve vacuum source is provided by a vacuum pump which is driven off the end of the right hand exhaust camshaft.

At idle the turbocharger wastegate solenoids are open. When the engine load and RPM increase under a wide open throttle, the turbocharger wastegate valves close to increase boost pressure. When the proper level of boost pressure is attained, the ECM will partially open the wastegates to maintain the boost pressure level. When the throttle closes, the ECM commands the wastegates to open to reduce the speed of the turbines.