Monitoring Function
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2010 BMW M6, 2010 BMW M5, 2009 BMW M6, 2009 BMW M5, and 2008 BMW M6. However, it is still accessible from the selected car via links, so may be relevant.
When the vacuum pump relay is energized and all monitoring conditions are met, the pressure sensor signal is delivered and the calculated pressure decline is compared to a threshold. If the pressure decline is lower than the threshold for more than 0.5sec, a pump error is set.