Map Sensor Inspection

A "Scan" tool reads manifold pressure and will display either volts or kPa of pressure.
^ Key "ON", engine stopped, (no vacuum), MAP will read high voltage or pressure, while at idle (high vacuum), MAP will read low voltage or pressure. Likewise, on acceleration, MAP will read high and on deceleration, will read low.
^ A failure in the MAP sensor, or circuit, should result a DTC 33 or 34.