Three symptom as described hint at a electronic issue like leaky capacitor. I'll be interested to see if somebody had the same experience.

Do you have a good scanner you can read the internal speed real-time to verify the DME knows the correct speed and the speedo just it's reporting wrong not that weird speed is also internal? I would definitely want to know.

You should get an abs/DSC error if the internal speed is wrong so I don't think so I would just confirm.

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