Audi A5 Cruise Control Failure: Common Causes & Fixes

As someone with moderate experience working on Audis, I had a very similar issue with my 2016 Audi A4. The cruise control suddenly stopped functioning, and the problem turned out to be a faulty brake pedal switch connection. After checking the error codes, my workshop found the cable connection to the pedal switch had become loose over time, causing intermittent cruise control failures. They also inspected the clock spring and speed sensor connections while diagnosing the issue, but these components were fine. The repair was relatively straightforward. The technician cleaned the connector, secured the wiring, and performed a system reset. Total cost was 95 Euro for diagnostic work and repair. The brake light was also occasionally flickering before the repair, which was resolved after fixing the connection. To provide more specific guidance for your A5, could you share: Are there any other warning lights on the dashboard? Does the brake light function normally? Have you noticed any other electrical issues recently? Does the cruise control fail to engage at all, or does it cut out while driving? These details would help determine if your issue is similar to what I experienced or if it might be something different.

Last serviced at 73351 KM and just noticed this issue recently. Symptoms are exactly as you described regarding the pedal switch, my brake lights also flicker occasionally. I checked the fuse box under the dashboard but all fuses seem intact. The cruise control completely fails to engage and no other electrical issues are present. The steering wheel buttons and other functions work fine, so I suspect the clock spring is not the culprit. Will try cleaning the brake pedal switch connections first based on your experience before visiting a workshop. Thanks for the detailed explanation about your repair costs.

Thanks for those additional details. Since your symptoms match exactly what I experienced with my A4, Im quite confident its the brake pedal switch connection. The intermittent brake light flickering alongside the cruise control failure is a telltale sign. When I had this issue fixed, the technician mentioned the pedal switch connector pins can accumulate dirt over time, causing poor contact. While cleaning the connections helped in my case, they recommended replacing the entire brake pedal switch assembly if the problem returns, as these components can degrade over time. A word of caution from my experience: when checking the pedal switch area, make sure the battery is disconnected first. Also, the throttle position sensor can sometimes show similar symptoms, but given your brake light issues, the pedal switch is the more likely cause. If cleaning the connections doesnt resolve it, expect around 150 Euro-200 Euro for a complete pedal switch replacement including labor. Much better than the 500 Euro+ I was initially worried about when the speed sensor or steering wheel components were suspected. Since youre at 73351 KM, its actually a common service point where these issues start appearing in our models.

Thanks for the thorough follow-up about the brake pedal switch issues. The matching symptoms, especially the flickering brake lights, make me feel better about tackling this myself first. Ill disconnect the battery and clean those connector pins this weekend. Your repair cost breakdown is really helpful, good to know a complete switch replacement would be 150-200 Euro if cleaning doesnt fix it. Much more reasonable than what I feared when the cruise control first failed. My A5 is pretty reliable overall, so finding out this is a common maintenance item at my current mileage helps put things in perspective. If I run into any issues during the cleaning, Ill be sure to get it properly diagnosed rather than risk damaging other components. Really appreciate you sharing your similar experience with the pedal switch, saved me some unnecessary worry about more expensive problems with the speed sensor or steering wheel systems.