Manifold Pressure/Vacuum Sensor: Description and Operation

Output Characteristic:

Manifold Absolute Pressure (MAP) Sensor:

This sensor senses a pressure change in the intake manifold and converts it into a voltage change. It consists of a semi-conductor type pressure converting element which converts a pressure change into an electrical change. An electronic circuit amplifies and corrects the electric change. The ECM sends a 5-volt reference voltage to the pressure sensor. As the manifold pressure changes, the electrical resistance of the sensor also changes. By monitoring the sensor output voltage, the ECM knows the manifold pressure (intake air volume).
The ECM uses the voltage signal from the MAP sensor as one of the signals to control fuel injection time, IAC valve operation, and EGR VSV valve operation.