If the heater/AC fan blows unexpectedly (not when it is supposed to, and sometimes when it isn't supposed to) it is often the Final Stage Resistor (FSR). It is essentially a part of the fan control circuit, but it is electronic, not just a resistor. It is fairly easily replaced. It is mounted under the dash. No coding is required. Do a search for a DIY article.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
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2003 X5 3.0 Steptronic, Premium, Titanium Silver
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