Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The positions of the turbocharger vanes are controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid to control the turbocharger vanes and a turbocharger vane position sensor to verify the vanes position. The ECM will vary the boost dependant upon the load requirements of the engine. The vane control solenoid has a high control circuit and a low control circuit. The ECM uses a pulse width modulation on both circuits to control the solenoid.