GLS Hybrid Air Suspension Problem

That sounds familiar. I had a similar issue with my old Audi A6, though it wasn't a hybrid. The leaning, error message, and inability to raise the vehicle all point to the air suspension. In my case, it was a faulty valve causing an air leak. Before assuming it's the bellows valve, check the air compressor and lines. A leak elsewhere could cause similar problems. Have you noticed the compressor running longer or more often than usual?

Thanks for the quick response. I haven't focused on the air compressor, but now that you mention it, I think it does run for longer periods. Where are the air lines located, and how can I check them for leaks? I don't have much experience with pneumatic suspension systems, so sorry if this is a basic question.

I understand your concern. Air line locations vary, but they usually run along the chassis rails, connecting to each shock and the compressor. Look for obvious damage. The best way to find small leaks is with soapy water. Spray it on the lines and connections while the system is pressurized; leaks will bubble. Given your description and inexperience, I strongly advise against DIY repairs. Improper handling can be dangerous. Consult a Mercedes mechanic for accurate diagnosis and safe repairs.

I appreciate the detailed explanation and advice. I won't attempt repairs myself and will schedule a Mercedes mechanic appointment. I still suspect the bellows valve. Thanks for sharing your experience; it's been helpful. The estimated 590€ seems reasonable. I'll post the final diagnosis and solution for others who might have similar issues.