Circuit Description
WARNING: This page is about a different car, the 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The barometric pressure (BARO) sensor responds to changes in altitude and atmospheric conditions. This gives the engine control module (ECM) an indication of barometric pressure. The ECM uses this information to calculate fuel delivery. The BARO sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The ECM supplies 5 volts to the BARO sensor on a 5-volt reference circuit, and provides a ground on a low reference circuit. The BARO sensor provides a voltage signal to the ECM on a signal circuit relative to the atmospheric pressure changes. The ECM monitors the BARO sensor signal for a voltage outside of the normal range. If the ECM detects a BARO sensor signal voltage that is too high, this DTC sets.