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Manifold Absolute Pressure Sensor

The Manifold Absolute Pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:

The Engine Control Module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a Wide Open Throttle (WOT). The MAP sensor is also used in order to determine the Barometric Pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The ECM monitors the MAP sensor signal for voltage outside of the normal range. If the ECM detects a MAP sensor signal voltage that is excessively low, DTC P0107 sets. If the ECM detects a MAP sensor signal voltage that is excessively high, DTC P0108 will set.

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