CAS: Comfort Access System
WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
The Car Access System (CAS) uses terminal 30g as follows to effect a time-controlled cutoff of control modules and components with power supply: Approximately 30 minutes after terminal R is switched OFF, the power supply for these components is switched off. This prevents the battery from being subjected to excess load by the electrical consumers for too long when the vehicle is out of use.