Circuit/System Description
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
The manifold absolute pressure (MAP) sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The powertrain control module (PCM) supplies 5 volts to the MAP sensor on a 5-volt reference circuit and provides a ground on a low reference circuit. The MAP sensor provides a voltage signal to the PCM on a signal circuit relative to the intake manifold pressure changes.