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 boost sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position (APP) and engine speed. The engine control module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The ECM supplies 5 volts to the boost sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The boost sensor provides a voltage signal to the ECM on a signal circuit relative to the pressure changes. The ECM monitors the boost sensor signal for voltage outside of the normal range. If the ECM detects a boost sensor signal voltage that is excessively low, this DTC will set.