Manifold Pressure/Vacuum Sensor: Description and Operation

Manifold Absolute Pressure/Barometric Pressure Sensor

MAP/BARO Sensor:

The Manifold Absolute Pressure/Barometric Pressure (MAP/BARO) sensor (Figure 10) is an input to the Powertrain Control Module (PCM). The sensor is used in conjunction with a MAP/BARO solenoid that either supplies manifold vacuum (MAP function) to the MAP/BARO sensor or opens the sensor to atmospheric pressure (BARO function). The PCM uses the MAP/BARO data to control the EVAP emissions system.

MAP/BARO Solenoid

MAP/BARO Solenoid:

The MAP/BARO solenoid (Figure 11) switches air flow passage between manifold vacuum and atmospheric pressure upon demand from the PCM. When voltage is supplied from the PCM, the MAP/BARO solenoid turns "ON". When "ON" the MAP/BARO sensor monitors barometric pressure (BARO); when the MAP/BARO solenoid is "OFF" manifold vacuum is monitored (MAP).