Mercedes S Klasse Stiff Steering Issue

Sounds familiar. I had a similar issue with my S Klasse. The symptoms you describe, the heavy steering and vibrations, are classic signs of steering sensor failure affecting the traction control. I would check the sensor replacement first, but before you do that make sure that there is no damage on the steering rack.

Interesting. When you say 'check the sensor replacement', do you mean physically inspect the sensor, or are you referring to replacing it outright? And did you notice any other warning lights or messages on your dash when your sensor failed? Like a traction control warning?

I meant replacing it. The sensor itself is likely faulty and causing the erratic readings. And yes, the traction control light illuminated intermittently when the angle sensor was failing. The car's computer uses the steering angle sensor to determine how much to apply the brakes individually to prevent skidding. If it gets bad data, all sorts of weird things can happen. I recommend a workshop visit. They will check the fault codes and suggest next steps.

Thanks, that confirms my suspicion. I appreciate the insight. I took it to my local independent shop, and they confirmed the steering angle sensor was indeed faulty. They replaced the sensor and recoded it. The final bill came to 195€ including parts and labor, which seems reasonable. Steering is back to normal now. Your experience helped me narrow down the problem and avoid unnecessary troubleshooting.