Renault Master Power Steering Fault

That sounds frustrating. I had a similar issue with my old Opel Corsa. My steering wheel was also vibrating. Have you checked the hydraulic fluid level? Low fluid can cause those symptoms. Also, have you looked at the steering pump? It might be failing. Did you check the steering column?

Thanks for the suggestions. I haven't inspected the steering pump or steering column yet. Could a defective cable or plug connection to the steering components cause these symptoms?

Yes, a defective cable or plug connection can definitely cause those symptoms. It happened to me with another car; it ended up being a faulty connection to the steering assist motor. I'd advise you visit a workshop to get it checked properly, as those components are important for safety.

I appreciate the confirmation and advice. I took it to a workshop, and it was indeed a defective plug connection. The repair cost me 95€. Thanks again for your help.