Circuit/System Description

WARNING: This page is about a different variant/trim than selected.

The supercharger inlet pressure sensor measures the pressure between the throttle body and the supercharger. Pressure in this area is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). The sensor provides a signal voltage that varies relative to pressure changes that occur from the various load and operating conditions of the engine. The engine control module (ECM) supplies a regulated 5 V reference circuit, and monitors the signal circuit.

Under normal operation the highest pressure that can exist in the supercharge intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is On while the engine is Off. The lowest manifold pressures occur when the vehicle is idling or decelerating. The supercharger inlet pressure can range from 20 kPa to as high as BARO.

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet pressure, manifold absolute pressure (MAP) and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing multiple models for the intake system. These models include the MAF Performance Test, MAP Performance Test 1, MAP Performance Test 2 and Throttle Position Performance Test, which are displayed on the scan tool.

The estimates of MAF, supercharger inlet pressure and throttle position from the system of models and calculations are compared to the actual measured values from the MAF, supercharger inlet pressure and the throttle position sensors to determine the appropriate DTC to fail.