SQ5 Cruise Control Failure Points to Throttle System

Had the same cruise control malfunction on my S4 2016 gasoline last month. The diagnostics revealed a faulty brake pedal position sensor actuator, which directly impacts the cruise control functionality. The car electronics were reporting false brake pedal signals, causing the system to disengage out of nowhere. Initially suspected the throttle body, but thorough testing showed the actuator connection was loose and partially corroded. The repair involved replacing the brake pedal position sensor and cleaning the connector pins. This was a relatively serious issue since it affected multiple safety systems tied to brake pedal monitoring. The non-functional cruise control is often misdiagnosed as a throttle body problem, but in many cases, its the brake pedal sensor causing these symptoms. A proper diagnostics scan should immediately identify if its sending incorrect signals to the control module. Worth mentioning that your symptoms match exactly what I experienced, error message on display and complete cruise control failure. Suggest getting it checked by a shop with experience in VAG car electronics.

Thanks for sharing that experience with the brake pedal sensor. The same cruise control failure happened on my 2014 Audi SQ5 and the steering wheel controls stopped responding too. The faulty system was driving me crazy with constant error messages. After diagnostic tests, it turned out the actuator and wiring harness needed replacement due to water damage. Did the fix hold up well since your repair? Also curious about the final cost, would help to know what repair costs to expect if its the same issue.

Thanks for asking about the repair results. The cruise control fix has been working perfectly since getting it sorted at the shop. The mechanic found a damaged cable connection at the actuator, which was causing the steering wheel controls and cruise control system to malfunction. The repair was straightforward, they replaced the faulty wiring and cleaned the connection points. Total cost came to 95 Euro for parts and labor, which seems reasonable considering the specialized diagnostic work needed to pinpoint the exact issue in the control system. Looking back, the constant error messages and non-responsive cruise control were definitely frustrating, but the fix has proven reliable. The fuse box and throttle body checked out fine during testing, it really was just that compromised cable connection causing all the trouble. A proper diagnostic scan was key to avoiding unnecessary parts replacement and zeroing in on the actual problem.

Thanks for the advice. After gathering the information here, I took my car to a different mechanic who specializes in car electronics. The initial diagnostic scan confirmed issues with the actuator wiring, similar to what others mentioned. They found water damage in the fuse box area that was affecting multiple systems. The repair involved replacing the damaged wiring harness and installing new protective covering to prevent future water intrusion. Total cost came to 280 Euro including parts and labor. The cruise control and all related functions are working perfectly now. No more error messages on the display. Much better experience this time with a specialist who knew exactly what to check. The faulty system is completely resolved and the car feels like new again. Really glad I got a second opinion instead of returning to my previous mechanic.