Circuit Description

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The position of the turbocharger (TC) vanes is controlled by the engine control module (ECM). The ECM utilizes a TC vane control solenoid valve and a TC vane position sensor to control the TC vanes. When the engine is not under load, the TC vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the TC vanes, thus increasing the boost. The ECM will vary the boost dependant upon the load requirements of the engine. The vane control solenoid valve uses 2 circuits, a control circuit and a low reference circuit. The ECM uses a pulse width modulation on the control circuit to open and control the solenoid valve. The ECM provides a ground on the low reference circuit. If the ECM detects any circuit failure, DTC P0045 will set.