RSQ3 Adaptive Headlight Control Module Issues

I had a very similar issue with my Q3 2012 last winter. As someone with moderate experience working on cars, I initially tried troubleshooting the lighting system myself, but quickly realized this was beyond basic DIY fixes. The symptoms were nearly identical, inconsistent beam adjustment and constant dashboard warnings. After diagnosis, the workshop found a faulty servomotor in the headlight assembly that controls the range control function. The headlight switch was working fine, but the servomotor wasnt responding properly to the light intensity sensor inputs. The repair involved: Complete diagnostic scan, Removal of headlight assembly, Replacement of servomotor unit, Recalibration of beam adjustment system, Testing of adaptive lighting functions Total cost was 1040 Euro including parts and labor. The repair took about 4 hours at the workshop. Before suggesting specific solutions for your case, could you provide: Exact build month/year, Current mileage, Whether you have xenon or LED headlights, When the problem first started, Any recent work done on the lighting system This information would help determine if your issue is similar to what I experienced or potentially something different.

Thanks for sharing those details. My RSQ3 just had its 30000km service last month. The auto-leveling system symptoms match exactly what you described. The constant beam adjustment issues and dashboard warnings started right after a deep wash at a car wash facility. This makes me suspect water might have affected the headlight control module or connections. Did your mechanic mention whether water damage was a possibility in your case? The 1040 Euro repair cost seems reasonable if it solves the headlight malfunction completely.

Thanks for the additional context about the timing of your issues. In my case, water intrusion was actually identified as the root cause. The electrical connectors for the headlight control module had corroded due to water seeping in through a damaged seal around the headlight housing. Since your problems started after a car wash, this strongly matches the pattern. The high-pressure water likely found its way into the headlight assembly, affecting the auto-leveling system and electrical components controlling the adaptive headlights. When my servomotor was replaced, the technician also: Replaced all weatherstripping around the headlight unit, Applied dielectric grease to electrical connectors, Installed updated seals designed to better prevent water ingress, Checked the light intensity sensors for proper operation The 1040 Euro repair has held up perfectly for over a year now, with no issues in wet conditions. The auto-leveling system works as intended, and the adaptive headlights respond correctly to driving conditions. Before proceeding with repairs, have the workshop check specifically for moisture damage and degraded seals. This could save you money if only the seals and connectors need attention rather than full component replacement.

Thanks for the feedback. It really helps to hear about similar experiences, especially regarding water damage being a potential culprit. The timing after the car wash definitely points to moisture issues. I booked my car in for next week and specifically mentioned checking the electrical connectors and seals around the headlight assembly. The auto-leveling system symptoms and constant headlight malfunction warnings are too similar to ignore, so I will have them inspect for water damage first. Will update once I know if it requires just new seals and connector cleaning or if I need the full servomotor replacement like in your case. The 1040 Euro cost gives me a good reference point for budgeting. Hopefully addressing any water intrusion points will prevent future issues with the light intensity sensors and adaptive lighting system. Really appreciate the detailed explanation of the repair process. Having this information helps me discuss the issue more knowledgeably with the workshop.