Two questions for those who have fixed key fob issues:

1. If I replace the battery in my diamond key (which works sometimes but not all the times), will the key just work or will it require resynchronization?
2. If I have a diamond key that has never worked, can I synchronize it using either a Foxwell or BMW Scanner? Or do you need something more powerful?

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2003 3.0 5MT Topasblau
Purchased in 2016 and sold in 2024
2012 35d Platingrau