Manifold Absolute Pressure (MAP)

The MAP sensor is mounted under instrument panel near right side A/C outlet. A hose from throttle body to MAP sensor provides vacuum signal. Sensor monitors changes in intake manifold pressure which result from engine load, speed and barometric pressure variations. As intake manifold pressure increases, additional fuel is required by engine. The MAP sends this information to ECM and ECM increases injector pulse width (time injector is open). As pressure decreases, pulse width is decreased.