Safrane power steering vibration

That sounds like a real pain. Spongy handling and increased steering effort definitely point to a power steering problem. When you say 'defective cable or plug connection,' have you checked the connections to the steering rack or the power steering pump itself? Also, have you checked the pressure hose for any leaks or kinks?

Thanks for the quick reply! When you say 'steering rack', is that the same as the whole steering system, or just a part of it? I did a quick look for leaks but didn't see anything obvious, I will double check the pressure hose more closely.

The steering rack is a key component of the whole steering system, it transforms the rotational movement of the steering wheel into the linear movement that turns the wheels. Since you've already checked for leaks, and you suspect electrical issues, it might be worth getting it checked at a workshop. Especially if you're seeing errors in the car's computer. A proper diagnostic scan can pinpoint the exact problem.

Thanks, that's helpful. I took your advice and brought it in to a shop. Turns out a faulty connection was indeed the culprit! They fixed the connection for 95€. Steering is back to normal. Appreciate the help!