Oil Pressure Switch -F22- And Reduced Oil Pressure Switch -F378-, Checking
WARNING: This page is about a different car, the 2012 Audi S5, 2011 Audi S5, and 2010 Audi S5. However, it is still accessible from the selected car via links, so may be relevant.
Check the oil pressure switch/reduced oil pressure switch in Guided Fault Finding using the vehicle diagnostic tester.