E60, E61, E63, E64 up to 09/2005:
WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2006 BMW 530i, 2006 BMW 525i, 2006 BMW 330xi, 2006 BMW 330i, and 2006 BMW 330Ci. However, it is still accessible from the selected car via links, so may be relevant.
The safety and gateway module (SGM) actuates the ECO valve in the power-steering pump. In a vehicle fitted with "Active Steering", the AL control unit determines the nominal current for the ECO valve in the power-steering pump. In the event of the AL control unit failing, the SGM assumes the default value of the nominal current.