Thanks for this great DIY and explanation thread!!
I believe I understand what is failing (parts become sticky) and why (dirt/wear/age). But I have a question as to why the warning light would be Yellow, then Red. What is the Yellow warning light trying to indicate? It seems to me that either the lock mechanism works, or it does not work. Why would there be a need for two level of warning lights (Yellow, then Red)?
In our case, we have a 2006 325xi and the Yellow warning light has been on since about one week ago. However, we HAVE NOT HAD any issue starting the vehicle, nor any issues with the steering wheel remaining locked. Nothing noticeably different other than the Yellow warning light.
I have heard mention of a service bulletin, but cannot find one specifically for this issue. Do you know the number of the SB specific to this issue?
I am betting (as the second owner of the vehicle) that the battery is original to the car. Has anyone made a link between the battery being low and this problem?