Manifold Absolute Pressure Sensor

The Manifold Absolute Pressure (MAP) sensor, mounted on left side of cowl, monitors vacuum signal to the EGR system. It senses the actual vacuum in the EGR vacuum line and sends a signal to the PCM.

The signal is compared to the EGR duty cycle calculated by the PCM. If there is a minor difference in the vacuum value sensed and the PCM command, the PCM corrects. When a major difference is sensed, the PCM recognizes a fault and sends a full EGR signal.