BMW Questions? Ask a BMW Repair Expert for Answers.
Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you
it could be the climate module, but also could be a faulty aux fan or any of several sensors.
the only way to verify the cause with certainty is to invest in a proper diagnostic with a factory level bmw scan tool which can monitor all sensors and components in the system and identify what part is preventing the AC from working. I would strongly advise against replacing the very expensive climate module prior to investing in this type of diagnostic.
if you need a good non dealer option to cut down on costs, check out www.bimmershops.com or www.bimrs.org for options.
Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you. Best wishes with your vehicle...