I recently got an OBD-II dongle with the Torque Android app, which allows me to read the computer's output in real time. The app will let me drag and drop different gauges on my screen, which works out great. However, there is a gauge for vacuum pump pressure, and I don't know why the vehicle (2008 Tundra) would have one.
So, what is the function of a vacuum pump in a modern engine, or is this just a label problem with the app?