Audi Q7 E-brake Malfunction: Control Unit Alert

As someone with moderate experience working on Audis, I had a similar issue with my 2018 Audi Q5. The brake sensor system showed identical symptoms, warning light staying on and parking brake refusing to engage properly. Initially thought it was just a brake switch problem, but the workshop discovered the electric motor in the brake calliper was defective. The vehicle safety system detected this fault and prevented the electronic parking brake from engaging to avoid potential damage. The repair required replacing the calliper motor assembly. Total cost came to 505 Euro, including diagnostic work and installation. The workshop completed everything in about 4 hours. Could you share some additional details about your Q7: Did the issue start suddenly or develop gradually? Are there any unusual sounds when engaging the parking brake? Have you noticed any other electrical system warnings? Does the regular brake system work normally? This information would help determine if your issue matches what I experienced with my Q5. The electronic parking brake systems are quite similar across the Q-series models from that period.

My issue started quite suddenly after a long highway drive. Currently at 149068 KM and just had the major service done last month. The regular brake system works perfectly fine, with no unusual sounds or behaviors. The brake fault warning only appears when trying to engage the parking brake. No other electrical warnings have appeared on the dash, which makes me think the brake switch or control module might be the culprit rather than the calliper motor. The parking brake worked flawlessly before this incident. Thanks for sharing your repair experience. The system glitch showing in my error memory seems different from your calliper motor issue, but its helpful to know the potential repair costs and timeframe. Will look into getting it diagnosed soon since vehicle safety is a top priority.

Having dealt with this exact issue on my 2018 Q5, your symptoms do sound different from my calliper motor failure. The absence of mechanical noise and the sudden onset after highway driving points more toward an electronic brake diagnostics issue rather than mechanical brake failure. After your reply, I had a chat with my mechanic who mentioned that highway driving in hot conditions can sometimes trigger brake system glitches in the control module. In my experience working with these models, when the regular brakes function normally but the parking brake shows a fault, it often indicates a control unit problem rather than a mechanical issue. A full brake diagnostics scan should be able to pinpoint whether its the brake switch or control module. Based on what you described, I suspect the control module might need a software update or reset, a much simpler fix than my calliper motor replacement. The system typically stores specific error codes that can distinguish between mechanical and electronic faults. Would you be able to share the exact error code from your diagnostic scan? This would help confirm if your issue matches any of the known control module problems in these models.

The diagnostic error code from my scan shows P888A, which seems to confirm the electronic control module theory rather than a mechanical issue. Your input about highway driving in warm conditions is particularly relevant since the brake fault appeared during similar circumstances. Getting more confident now that this might be a control module reset or software update rather than an expensive component replacement. The brake diagnostics scan was definitely worth doing before heading to the workshop, as it helped narrow down the possible causes. Will schedule an appointment with a certified workshop that specializes in electronic brake systems. The regular brakes continuing to work normally is reassuring from a vehicle safety perspective, but want to get this resolved quickly to ensure the parking brake functions properly. Thanks for all the detailed feedback and sharing your repair experiences. Having this information makes me feel better prepared for the workshop visit and helps avoid unnecessary part replacements.