Diesel Data: Automotive Repair

Manifold Pressure/Vacuum Sensor: Description and Operation

PURPOSE/OPERATION
The manifold absolute pressure sensor converts the intake manifold pressure to a Voltage value and inputs it to the powertrain control module. The powertrain control module uses this signal and the engine r/min. to calculate the basic fuel injection timing. 5 Volts of power is supplied to the manifold absolute pressure sensor from the powertrain control module, and the sensor circuit ground is located in the powertrain control module. The manifold absolute pressure sensor output Voltage is proportioned to the intake manifold vacuum or pressure and sent to the powertrain control module.