A3 Air Suspension Failure: Lean & Error Message Alert

Had almost the exact same issue with my 2006 A4. As someone with moderate experience working on cars, I initially tried diagnosing the pneumatic suspension problem myself using basic diagnostic tools, but quickly realized this needed professional attention. The symptoms you describe match what I experienced, uneven ride height, error messages, and that distinctive tilt to one side. The air suspension system was basically failing to maintain proper pressure due to a defective bellows valve. Took it to a workshop specializing in suspension systems. They confirmed the bellows valve failure through proper diagnostics and replaced the faulty component. Total cost was 590 Euro, but it completely resolved the issues. The car now maintains correct ride height and the error messages are gone. Before you proceed with repairs, could you share: Has the issue developed gradually or suddenly? Are you hearing any hissing sounds from the suspension? Which corner of the car is showing the most noticeable drop? Have you noticed any changes in ride comfort before this started? This information would help determine if your issue is identical to what I experienced and whether you might be looking at the same repair solution.

Thanks for the responses so far. My car has 119520 KM and just had its yearly service last month. The suspension issue developed quite suddenly, within a week it went from normal to noticeably problematic. There is a clear hissing noise coming from the rear passenger side shock absorber area when the car is parked. The car drops most noticeably on that same corner after sitting overnight. The ride quality has definitely gotten worse over the past month, especially over bumps and at highway speeds. Based on the responses, it does sound like my air suspension needs professional diagnosis. Will get it checked at a suspension specialist before risking any further damage to the system.

Thanks for providing those extra details. Based on what you're describing, especially the hissing noise from the rear passenger side, your symptoms are remarkably similar to what I experienced. In my case, that same corner had a failing air spring that was leaking. The sudden onset matches my experience too. My suspension failure progressed rapidly once the hissing started. The overnight dropping is a clear sign of an air leak in the suspension system, likely from either the air spring or connecting valve. I had initially considered just replacing the shock absorber, but the complete diagnosis revealed the air spring was the core issue. The complete repair included: New air spring unit, Replacement bellows valve, System pressure test, Full calibration Total repair cost was around 780 Euro, but prices can vary based on parts availability and labor rates. Word of caution from my experience: continuing to drive with these symptoms risks damaging other suspension components. When my air spring failed, it put extra stress on the remaining suspension parts. The yearly service likely wouldnt have caught this as its a separate suspension system issue that typically requires specific air suspension diagnostics.

Thanks everyone for the helpful responses. Just wanted to update that I took the car in today to a suspension specialist. They confirmed exactly what was suspected, a faulty air spring and bellows valve on the rear passenger side were causing the suspension system issues. The complete diagnosis showed the shock absorber was still in good condition, but the air leak was causing irregular ride height and putting stress on other components. They recommended replacing both the air spring and bellows valve as a set to prevent future issues. Total repair cost came to 820 Euro including: New air spring, New bellows valve, Full system calibration, Labor costs The car now maintains proper ride height, the hissing is completely gone, and the suspension feels smooth again. Really glad I caught this before it caused damage to other parts of the suspension system. Will definitely keep an eye on any future changes in ride quality or height adjustments. Thanks again for helping me identify the issue and pushing me to get it properly diagnosed.