Manifold Absolute Pressure Sensor

The Manifold Absolute Pressure (MAP) sensor measures changes in manifold pressure. MAP sensor is located on top of intake manifold. See Figure . 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 PCM (1.5 volts at idle to about 4.5 volts at wide open throttle). The PCM can monitor these signals and adjust air/fuel ratio and ignition timing under various operating conditions.

If MAP sensor fails, the PCM 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.