MAP - Manifold Absolute Pressure

Indicates voltage signal from MAP sensor. Voltage readings are low when manifold pressure is low (high vacuum), and signals increase as manifold vacuum decreases. With ignition off and engine stopped, manifold pressure is equal to atmospheric pressure and voltage signals will be high (nearly 5 volts). With engine running, normal readings are 1-2 volts.

Comparison of sensor readings with readings from known good sensor can be used to isolate malfunctioning sensor. Sensors have a color code tab in the connector cavity, and sensors with the same colored tab have identical calibration. Readings from sensors with like identification tabs should be the same to within ±.4 volt.