Seat Leon Air Suspension Problem

Sounds like a potential air leak in your pneumatic suspension system. Have you checked the air lines and connections for any obvious damage or wear? Sometimes a visual inspection can reveal the source. Could also be the compressor itself struggling to maintain pressure. Is the compressor running longer than usual? Also, are you certain it's not just a faulty sensor giving a false reading?

I haven't checked the compressor directly. Where exactly would I find the air lines and connections to inspect them? Also, how would I diagnose a faulty sensor? Is there a way to test it?

Okay, given the leaning and the error code, it's likely a valve issue as you suspected, preventing proper air distribution. While you could try tracing the lines, diagnosing a sensor without proper equipment is tricky. Honestly, with those symptoms, you're probably best off taking it to a workshop that specializes in air suspension. They'll have the tools to pinpoint the exact problem. Could still be an air leak, but valve failure is a strong possibility. That would explain the bumpy ride and leaning issue.

Took it to the shop. Correct, faulty air suspension bellows valve. Repair cost me 590€. Thanks for the help.