Fit Blower Motor AUC Sensor Issue

I find your analogy of a needle in a haystack to be somewhat accurate in this situation, particularly if you lack specialized diagnostic equipment. The AUC sensor, sometimes referred to as a BMW AUC due to its common usage in that marque, influences the automatic recirculation function based on detected pollutants. While a defective connection is plausible, the complexity of modern vehicle electronics necessitates caution. It's not merely about checking continuity; the sensor transmits data to the vehicle's ECU. Have you consulted the vehicle's diagnostic trouble codes (DTCs)? A relevant code could provide a more precise direction for your troubleshooting efforts. Without this, you could be chasing ghosts.

Thanks for the reality check! DTCs, right. Makes sense. I figured probing around blindly was a recipe for disaster. So, let's say I do pull a code pointing to the AUC sensor. What then? Is it a straightforward 'replace and pray' situation, or are there specific voltage readings or resistance values I should be looking for before I throw parts at it? Because I really want to avoid the 'replace and pray' scenario, and also avoid a trip to the mechanic if I can. Also, does the ECU need to be reset after a replacement?

Given that you are expressing a desire to avoid unnecessary component replacement, allow me to elaborate. Assuming a DTC confirms the AUC sensor's malfunction, further investigation is still warranted. Consult the vehicle's service manual for the correct voltage and resistance specifications. If these values deviate significantly, then replacement is likely necessary. However, bear in mind that while ECU reset may be advisable, it is prudent to proceed to a competent workshop. This will ensure appropriate calibration of the new sensor, and avoid any potential system conflicts arising from inaccurate configuration. With a repair cost of approximately 95€ it might be more affordable than additional guesswork.

The shop visit paid off. You were spot on. Took it to a trustworthy shop, explained my suspicions, and showed them the DTC. Turns out, the AUC sensor cable was indeed corroded. They cleaned it up, reconnected everything, and boom! Blower's working like new. Paid 95€ and now I'm a happy camper. Thanks for the advice on checking the DTC and going to the workshop, it saved me a lot of time and potential headaches.