Circuit Description
WARNING: This page is about a different car, the 1996 Pontiac Bonneville, 1996 Oldsmobile LSS, 1996 Oldsmobile Eighty-Eight, and 1996 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Manifold Absolute Pressure (MAP) sensor measures changes in intake manifold pressure (vacuum). A low voltage signal, 2 volts, is sent to PCM on signal circuit at closed throttle (high vacuum). A high voltage signal, 4 volts is sent at wide open throttle (low vacuum). A substantial change in MAP signal should be preceded by a change in throttle position.