Manifold Absolute Pressure Sensor (2.2L)

The Manifold Absolute Pressure (MAP) sensor measures changes in manifold pressure. Changes in manifold pressure result from engine load and speed changes. The MAP sensor converts these changes in manifold pressure into a voltage output signal to ECM (1.5 volts at idle to about 4.8 volts at wide open throttle). The ECM can monitor these signals and adjust air/fuel ratio and ignition timing under various operating conditions.

If MAP sensor fails, the ECM substitutes a fixed MAP value, and uses the TP sensor to control fuel delivery. A fault in the MAP circuit should set a related diagnostic trouble code.