Supra Air Suspension Failure

Sounds familiar. Had the same issue on my old Audi A6. Check for error codes first. Likely a defective suspension air bag valve causing an air leak.

Where exactly should I be looking for this valve? Is it something I can even check myself without special tools? I'm not super mechanically inclined, but I'm willing to try.

Honestly, on the Supra it's probably best left to a professional. It’s likely the bellows valve, but finding the exact location and confirming requires some disassembly. Could save you money in the long run by not making it worse. Get it scanned and they'll tell you for sure.

Thanks a bunch for the advice! Took it to the workshop, and you were spot on – faulty air suspension bellows valve. Repair cost me 590€, but at least it's fixed now!