Manifold Pressure/Vacuum Sensor: Description and Operation

Position
Located in the engine compartment and connected by a vacuum pipe to the intake manifold/charge air distribution pipe.






Design


Task
Detecting the intake manifold/ charge air distribution pipe pressure and supplying a signal to the engine control module.

Function
The pressure in the intake manifold/charge air distribution pipe alters the shape of the diaphragm and the piezo resistors alter their resistance. This influences the output voltage which in turn is used by the engine control module as information regarding the pressure in the intake manifold/charge air distribution pipe. The intake manifold/charge air distribution pipe pressure is required for the following funtions:
- Limiting quantity injected at full load
- Exhaust gas recirculation (EGR)
- Intake pressure control/boost pressure control
- Calculating of air mass
- Forming substitute value in the event of failure of HFM-SFI