I said in one of the previous articles that the interior heating didn’t work properly in the beginning. The diagnostics revealed the cause in the small fan located inside the panel, which was originally supposed to suck air from the interior for the unit to adjust the temperature due to AC settings. The fan, rather its motor, was broken, which led to a stalled hot air inside the climate panel and thus cold air in the interior to cool down the heat.

As an experienced theoretical expert I knew the new climate panel cost nearly 1000€, whereas used parts could be purchased for ten times less. I also knew the parts were exchangeable in a plug-n-play way. The only important thing was to purchase the correct panel because there are basically two types – an unit with either MAX or REST button. Mine was REST so after a quick search, I ordered one piece on eBay from Lithuania for 150€. A day later my BMW expert friend mocked me for spending that much money and told me our local market and community offered these parts for prices around 30€. Well, next time…

The eBay item arrived two days later and the timing was just right because on the same day I picked up my dials and radio from the expert on dead pixels issue. So on that afternoon I went onto the interior reassembly, plus removal of a fixed anti-radar device that had come with the car.

As much as I don’t consider myself a total mechanical loser, the operation took me nearly two hours as I was extremely cautious and careful, not to damage anything. In the end, everything was fine. Dials, radio and new climate panel were mounted, anti-radar removed. I put all trims and plastics together and enjoyed the view on the final product. Nice!

The new climate control panel was in place and it was time to verify its workings. On the next occasion I realized the car did start to heat but the air distribution was not right. From the middle vents only cold air was blowing, whereas the rest of the vents worked find.

Extensive research and diagnostics came out with several errors, which led me – with some assistance from the community experts – to a simple conclusion. The panel from Lithuania came from an E39 but not from an M5. Meaning, there might be a possibility that the panel just did work towards settings from a different model. To fix, I needed to proceed with some coding. Because I managed to purchase a cable and a proper diagnostics/coding software in the meantime, I figured the panel originated in a diesel E39 with an auxiliary heating.

The fix was then rather quick. I just let the car overwrite the panel and IHKA unit with the default M5 values. And the heating/cooling has been working since then with no issues at all.