Audi Q8 Active Hood Fault Triggers Safety System Alert

As someone with some hands-on experience with German luxury vehicles, I encountered a very similar issue with my 2021 Audi Q7. The crash detection system triggered unexpectedly, showing identical symptoms, airbag light and hood fault warnings. The problem turned out to be a faulty acceleration sensor that was incorrectly signaling an impact to the car safety systems. The pedestrian safety features, including the active hood mechanism, were activating without any actual collision. The repair involved: Full diagnostic scan, Replacement of the defective impact sensor, Resetting and recalibrating the collision detection system, Checking all hood actuator connections Total repair cost was 315 Euro, including parts and labor. The workshop completed everything in about 3 hours. To provide more specific guidance, could you share: Have you noticed any other warning lights? Did this start happening after any specific event (car wash, battery disconnect, etc)? Does your Q8 have the latest software updates installed? Are there any unusual noises from the hood area? This information would help determine if your issue matches my experience or might be something different.

Thanks for the detailed response. My Q8 has 111319 KM and just had its annual service last month. After your message, I checked and noticed a slight clicking sound near the hood latch when walking around the front of the vehicle. The car electronics seem otherwise normal, with no additional warning lights beyond the initial system fault warnings I mentioned. The issue started out of nowhere during normal driving, no car wash, battery work, or other maintenance was done recently. Ill have the dealer check the acceleration sensor you mentioned since the symptoms match exactly. The hood safety mechanism being triggered without impact definitely sounds like the same problem.

Thanks for the additional details about your Q8. The clicking sound you're hearing near the hood latch actually reinforces my initial diagnosis about the faulty impact sensor. On my Q7, I also noticed similar clicking noises before getting it fixed, its the pedestrian safety system partially activating. The fact that this started during normal driving, with no external triggers, is very typical of a failing collision detection sensor. The high mileage could be a factor, as these sensors can degrade over time. When the workshop repaired mine, they mentioned that false triggers of the active hood system are a known issue when the impact sensors start failing. The system fault you're seeing is the cars safety system detecting these incorrect signals. One thing to note, once this is fixed, make sure they perform a complete system reset. In my case, they had to clear all error codes after replacing the sensor to prevent any lingering system faults from causing issues. Would you mind updating the thread after your dealer visit? It would be helpful to confirm if the repair solution was similar to mine.

Thanks for all the helpful information. I took my Q8 to the dealer today and you were spot on, it was indeed a faulty impact sensor triggering the pedestrian safety systems incorrectly. They found the front crash sensor was sending erratic signals, causing the hood actuators to partially engage. The repair ended up costing 290 Euro, slightly less than your case. They replaced the faulty sensor, reset all the car electronics, and recalibrated the entire safety system. The clicking noise is completely gone now and all warning lights have cleared. For anyone else who might encounter this issue: the key symptoms were: Active hood fault warning, Airbag warning light, Clicking sounds near hood, System fault warnings, No actual impact or accident The car sensor replacement took about 2.5 hours total. Everything is working perfectly now. Really appreciate the guidance, it helped me understand the issue before going in for service.