Giulia Cruise Control Dies: Speed Sensor May Be Culprit

I had an almost identical issue with my Alfa Romeo Stelvio from 2019. As someone with moderate experience working on cars, I initially thought it might be a blown fuse, but the fuse box inspection showed everything was fine. After some troubleshooting, I took it to my regular workshop. They found that the issue was actually related to a faulty connection between the throttle position sensor and its wiring harness. The connector had developed corrosion, causing intermittent contact problems. The speed sensor was testing fine, but the poor connection was preventing proper communication with the cruise control module. The repair involved cleaning the connector and replacing a damaged section of the wiring. Total cost was 95 Euro, which included diagnostic time. The fix took about an hour, and the cruise control has worked flawlessly since then. What year is your Giulia and have you noticed any other electrical issues? Also, does your check engine light come on, or are there any other warning lights on the dashboard? This information would help narrow down if you are dealing with a similar issue or something else entirely. A proper diagnostic scan would show exactly which sensors are communicating properly, especially the speed sensor and throttle position readings. These readings are crucial for cruise control operation.

Thanks for sharing your experience. In my Giulia (93766 KM), I have not noticed any check engine lights or other electrical issues. The cruise control simply stopped working without warning. After reading your response, I checked my brake lights since these can also trigger cruise control problems through the pedal switch system. All brake lights work normally. I will get the speed sensor connections checked as you suggested, since intermittent wiring issues seem like a plausible cause. My concern is that a blown fuse might be the simple fix, but I cannot locate the specific cruise control fuse in the manual. Would really appreciate if someone could point me to the correct fuse location before I take it to a shop.

Thanks for the update on your Giulia. After my previous experience with the connector issue, I would still suggest checking the fuse box thoroughly. The cruise control fuse in our models is actually shared with several other functions and is located in the main fuse box under the hood, labeled as F35. Its technically labeled as the Body Control Module fuse, which handles multiple systems including cruise control. Since your brake lights are working fine, we can probably rule out the brake pedal switch. The fact that you have error codes stored but no warning lights is very similar to what I experienced. While my issue ended up being the connector, another common failure point is the clock spring in the steering wheel, which carries the signals from the cruise control buttons. Before heading to a shop, try this: check fuse F35, and also listen for any unusual clicks or feels from the steering wheel buttons when you press them. A failing clock spring often causes intermittent function before complete failure. If the fuse looks good and theres no obvious steering wheel button issues, then professional diagnosis would be the next step, focusing on the speed sensor connections we discussed earlier. The diagnostic scan will quickly pinpoint if its a wiring issue like mine or something else.

Thank you for the detailed information about the fuse location and the clock spring possibility. I checked fuse F35 as suggested, and it appears to be in good condition. When testing the steering wheel buttons, I did notice they feel slightly mushy compared to normal, which might indicate your clock spring theory could be correct. I tested all cruise control related functions again today, including all steering wheel buttons, and noticed something new, there is a very faint click sound when pressing the cruise control buttons that wasn't there before. Based on your experience with connector issues and this new observation about the buttons, I suspect the clock spring might indeed be the culprit. I will schedule an appointment to have the system properly diagnosed, with special attention to the clock spring and speed sensor connections. The pedal switch seems fine since brake lights work normally, but I will have them check the entire cruise control circuit just to be thorough. Would you mind sharing what diagnostic codes you had when your connector issue occurred? My scanner shows P0503 and P0571, which might help others who encounter similar symptoms in the future.