Diagnostic Overview
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.
To support a sufficient vacuum in the brake booster under all conditions, a vacuum pump is installed at the brake booster. The pump is controlled by a vacuum sensor.
If the sensor or the vacuum pump is malfunctioning, catalyst heating is disabled and cyl 6-10 are deactivated to ensure an error-free operation of the brake system.
In this case the engine emissions are affected.
Apart from the electrical diagnostics (short to batt, short to ground, open load) the brake booster vacuum sensor monitoring looks for permanent deviations of the measured value from a calculated value to detect a sensor drift.
When the difference exceeds an threshold (200mbar) for a certain time (<60sec), the vacuum sensor malfunction code is set.