Circuit/System Description

The turbocharger pressure sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load, and turbocharger boost. The engine control module (ECM) supplies 5 volts to the turbocharger pressure sensor on the 5-volt reference circuit. The ECM provides a ground on the low reference circuit. The turbocharger pressure sensor provides a signal to the ECM on the sensor signal circuit which is relative to the pressure changes in the manifold. The ECM detects a low signal voltage at a low MAP, such as during deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at idle. The barometric pressure (BARO) sensor is internal to the ECM. This location allows for constant monitoring of the barometric pressure. The ECM compares the turbocharger pressure sensor signal to the internal BARO sensor signal when the ignition switch is turned ON, with the engine OFF.