The boost pressure sensor is located inside the intake pipe in front of the throttle valve. The Sensor measures the pressure and sends the data to the engine management system. With the boost pressure data the engine management calculates the turbo boost pressure for turbocharged engines and the fuel injection values for naturally aspirated engines.

In case of a defective boost pressure sensor the engine management system will issue a diagnostic trouble code and ignite the check engine light.

In addition to that the engine will generate less power, use more fuel or even go into emergency mode.

The boost pressure sensor is located inside the air stream so it is prone to pollution. Other common failure reasons can be corrosion or cable damage.