Manifold Pressure/Vacuum Sensor: Description and Operation

MAP Sensor:

MAP Sensor Output Characteristic:

The Manifold Absolute Pressure (MAP) sensor signals the ECM of pressure changes in the intake manifold. It consists of a semi-conductor type, pressure sensitive element which converts a pressure into an electrical resistance. The ECM sends a 5.0 volts reference voltage to the MAP sensor and reads the voltage drop caused by the resistance. As the manifold pressure changes, the electrical resistance of the sensor also changes. By monitoring the sensor output voltage, the ECM senses the manifold pressure (intake air volume). The ECM uses the voltage signal from the MAP sensor as one of the signals to control fuel injectors, ISC solenoid valve and EGR VSV (if equipped).