Adam Tire Pressure ABS Issues

That's a strange combination of symptoms. A faulty tire pressure sensor could trigger the warning light, but the ABS and steering issues seem unrelated at first glance. Is the tire pressure actually consistent across all tires, even after driving a bit? Sometimes a very slow air leak can be hard to detect immediately.

I rechecked the tire pressure after driving. All tires seem to be holding pressure. Could a defective valve in the tire cause all these issues?

A defective valve could certainly cause a slow leak you might not immediately notice, potentially triggering the tire pressure warning. However, the ABS and steering issues suggest something more. It's possible the low tire pressure (even if seemingly within range) is affecting the ABS sensors, or there's a separate issue causing the other problems. I'd recommend getting it checked out at a workshop. It might be more complex than just a tire valve.

Thanks for the input. Took it to the workshop, and you were right. Defective valve was the culprit for the tire pressure warning, and it was affecting the ABS. Repair cost 280€.