Manifold Pressure/Vacuum Sensor: Description and Operation

MAP Sensor:

MAP Sensor Output Characteristic:

DESCRIPTION
The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure (vacuum). The MAP sensor consists of a semiconductor type pressure converting element, which converts a pressure change into an electrical change, and an electronic circuit which amplifies and corrects the electrical change (refer to accompanying images).

OPERATION
The Powertrain Control Module (PCM) applies 5 volts to the MAP sensor. The change in the pressure, that results from the engine load and RPM changes, is converted into a voltage input that is monitored by the PCM. A low voltage reading at the PCM indicates low manifold pressure, and a high voltage reading at the PCM indicates high manifold pressure.