Mine never slow cranked but it just outright ignored the start button press on increasing frequency. For about a year every month or two it would take 2-3 presses. Then a couple months ago many many presses over 10 minutes no start.

After about ten minute pause it started first press and I drove about 75 minutes to my best friend's heated garage where I replaced the starter the next day. (I had the part in my car for months waiting for a more direct signal that it was the motor not the start button etc).

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)