Manifold Pressure/Vacuum Sensor: Description and Operation

SCORPIO

The manifold absolute pressure sensor measures the manifold vacuum by means of a frequency, then provides a signal to the ECA proportional to engine load. The ECA uses this signal to modify air/fuel ratio, spark timing, idle speed and EGR flow. Do not use a voltmeter or ohmmeter to check the MAP sensor, as this may damage the sensor. Use of Rotunda tool No. 105-00001 or equivalent in conjunction with a digital volt-ohmmeter is necessary to check frequency output.