Manifold Absolute Pressure Sensor (MAP)

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