Q4 e-tron HVAC Controls Dead, Possible Control Unit Failure

Had the same climate control issues on a 2020 Audi e-tron GT. The symptoms matched exactly, unresponsive controls and minimal air flow. The root cause was a faulty wiring harness connecting the climate control module to the main power supply. Electrical connectors had developed corrosion due to moisture intrusion, causing intermittent connection issues. This affected both the control panel functionality and power delivery to the HVAC components. The repair required: Complete removal of the dashboard, Replacement of the main wiring harness, New electrical connectors for the climate control unit, System diagnostic reset This was a serious issue that could have led to complete HVAC system failure if left unaddressed. The problem is fairly common in EV models due to the complexity of their electrical systems. Would recommend having a certified EV technician check specifically for: 1. Corroded electrical connections 2. Damaged wiring harness 3. Power supply voltage to the control module 4. Control panel communication errors These symptoms typically indicate an electrical rather than mechanical issue.

Thanks for sharing your experience with the wiring harness issue. I had almost identical problems with my Q4 e-tron last winter, really frustrating when the HVAC system just stops working properly. The blower motor would barely spin and the control panel was completely dead most mornings. My local shop also found corroded connectors affecting the power supply to the climate control unit. Did you end up getting any warranty coverage for the repair? Would be helpful to know the cost since my warranty just expired and I want to budget in case the problem returns. Also curious if youve had any other electronic faults pop up since getting it fixed?

Glad I could help, wanted to update that my HVAC system has been working flawlessly since getting it repaired. The electronic faults with the climate control panel were completely resolved after replacing the corroded cable connections near the power supply unit. The total repair cost was 95 Euro for fixing the faulty connector, much less than initially expected since no complete wiring harness replacement was needed. My case turned out to be simpler than first diagnosed. No other electronic faults have appeared in the last 6 months since the repair. The climate control system now responds instantly, the blower works at all speeds, and the temperature regulation is precise. The key was having a technician who properly diagnosed the specific connection issue rather than assuming a full wiring harness replacement was required. The HVAC system in these EVs is quite reliable once electrical connection issues are properly addressed. Regular inspection of the connectors can help prevent future problems.

Thanks for the feedback. After visiting a specialized EV repair shop last week, they found similar electrical connector issues affecting the climate control system. The blower motor would out of nowhere cut out due to corroded wiring near the main power supply. Total repair cost came to 320 Euro, they had to replace several electrical connectors and clean up some corrosion damage. The HVAC system is now working perfectly again. The air conditioning kicks in immediately, and the control panel responds like new. The shop mentioned these connection problems are somewhat common in EVs and recommended annual inspections of the electrical systems to catch any early signs of corrosion. Really glad I got it properly diagnosed this time instead of continuing with temporary fixes that werent addressing the root cause. No other issues since the repair. Finally have reliable climate control again just in time for the changing weather.

Hello, I have a new Audi Q4. Problem is that everything shuts down while driving. This has happened 4 times already. The first 2 times the car had only driven about 500 km. I took the car to the garage and they checked everything, but they couldn't find anything. Because I had no proof, no photos etc., I was dismissed with "you only have a complaint". Now, at about 1950 km, while driving about 50km, I felt the need to pull over to the side of the road because a car was driving behind me, honking and waving at me as it passed. Now I have reported the complaint to Audi again because this is not normal. How should I proceed with this? It's very dangerous. I would appreciate your response.

(Translated from Dutch)

This is indeed a serious safety concern. Since the issue involves the entire vehicle shutting down while driving, it could be related to a critical electrical fault or a software issue. I recommend documenting each occurrence with as much detail as possible, including the conditions when it happens (speed, weather, road type, etc.). Take your vehicle back to the dealership and insist on a thorough inspection, highlighting the safety risk. Request that they check for any software updates or recalls that might address this issue. If the problem persists, consider seeking a second opinion from another authorized Audi service center. Please keep me updated on your progress, and let me know if you have any further questions.