5) Check the electropneumatic pressure converters (=EPDW)
WARNING: This page does not describe the selected car, but rather 45 other vehicles, including the 2016 BMW M5, 2016 BMW 550i xDrive, 2016 BMW 550i, 2016 BMW 535i xDrive, and 2016 BMW 535i. However, it is still accessible from the selected car via links, so may be relevant.
The electropneumatic pressure converters are activated individually so that -450hPa is routed to the wastegate. The adjustment of the wastegate can be partially observed from above. During the activation, the vacuum can be checked using a manometer, if necessary. If the vacuum line is disconnected, a delay of the pressure build up is to be observed!