So ... There is hope. When you wrote "that does not do anything", I assumed the procedure literally did nothing at all. There have been numerous posts about this issue with several different makes and models. It seems like there are as many different "fixes" as there are posts from folks that have resolved this on their own. In this following thread, users have posted several how to remedies. https://community.cartalk.com/t/how-did ... n/52935/21
Wow! I'm impressed and I learned something new for a very unusual condition. Thank you for sharing your success and how you achieved it. Knowing how this speedometer functions, I thought the use of a magnet would make sense when I read something about a magnet fix in that post. Explaining the physics of why this worked would sound boring so I'll just agree, it's "like magic".