Audi RS4 Cruise Control Dies Without Warning

Having some experience with a similar issue on my RS5 from 2 years newer than yours, I can share what worked for me. The cruise control symptoms you describe match exactly what I experienced. After the steering wheel controls seemed unresponsive, my workshop found a faulty cable connection between the cruise control module and the throttle position sensor. The connection had worked loose over time, causing intermittent function before failing completely. The repair involved accessing the wiring harness and replacing the damaged connection points. Total cost was 95 Euro including diagnostic work. Since the fix, cruise control has worked flawlessly. Could you share: Build year of your RS4, Current mileage, Whether the check engine light is also on, If you notice any other electrical issues This info would help determine if you are facing the same root cause. While checking fuses was a good first step, the pedal switch and wiring connections are common failure points in this model range that require proper diagnosis.

Thanks for the feedback! My last service was done 2 months ago at 73513 KM. The mechanic actually mentioned the clock spring might need replacement soon but didn't flag any other potential issues. Based on what you described, I suspect my problem could be different since my check engine light stays off and all other electrical systems work fine. The cruise control still shows signs of life by lighting up briefly, which makes me think the pedal switch might be the culprit. Will get it properly diagnosed and report back with findings.

Thanks for the update. The clock spring mention from your mechanic is actually quite relevant here, as its wear can cause intermittent cruise control issues similar to what you describe. While my RS5 problem was wiring related, clock spring failure often shows these exact symptoms, the cruise control light flashing briefly before deactivating. The fact your check engine light stays off actually aligns more with a clock spring issue than the wiring problem I had. When my throttle position sensor connection was faulty, it triggered multiple warning lights. A failing clock spring typically costs 200-350 Euro to replace, including labor. The good news is once replaced, it usually resolves not just cruise control problems but can also improve other steering wheel control functions. Since your mileage is relatively low at 73513 km, getting this addressed soon could prevent more extensive issues. When my control module wiring needed repair, I waited too long and ended up with complete system failure. Would be interested to hear what the diagnostic scan reveals. The scan tool should quickly determine if its the clock spring or something else in the cruise control system.

My original concerns about the cruise control seem to point toward the clock spring issue you mentioned. Getting the diagnostic scan makes even more sense now, especially since you encountered a similar dashboard light behavior with your clock spring problem. The cost estimate of 200-350 Euro is actually lower than I feared, considering some forum posts mentioned much higher repair bills for cruise control problems. I will schedule the diagnostic next week and make sure they check both the pedal switch and the clock spring thoroughly. What you mentioned about the warning lights makes sense, since my check engine light stays off, that does suggest a different root cause than your throttle position sensor connection issue. Really good to know this should be addressed soon rather than waiting for complete failure. Will definitely update once I get the speed sensor and other components properly checked. The fact that other electrical systems work normally does align with what you described about clock spring symptoms.