Smart Fortwo Steering Shake & Power Loss, Critical Fix

Had the same problem on a 2012 Smart Forfour. The steering wheel started shaking and the power steering became extremely heavy, making parking quite difficult. The main cause was a faulty connection in the electric power steering wiring harness. The problem got worse over time, causing intermittent power steering failures and dashboard warnings. The steering rack was fine, but the electrical connections had corroded, disrupting signals between the control module and steering system. The repair involved replacing the wiring harness and cleaning the connection points. This was a serious issue since faulty power steering can lead to loss of control. The steering pump and mechanical components were thoroughly checked but showed no damage. After the repair, the wheel alignment was also done to ensure proper handling. The power steering warning light went off immediately and the steering feel returned to normal, light and responsive without any vibration. This is a known weak point in these models. Best to get it checked soon, as continuing to drive with compromised steering can damage other components in the system.

Thanks for the detailed reply. It sounds exactly like what I am experiencing with my Smart Fortwo right now. The heavy steering and shaking are really concerning. Do you remember roughly how much you paid for the wiring harness replacement and labor? Also curious if the steering system has given you any more trouble since getting it fixed? My steering column feels particularly loose when turning left, which makes me wonder if there might be additional issues beyond just the wiring. The electric steering system in these cars seems quite sensitive to electrical problems.

Great news, since my Smart Forfour was repaired, the electric steering has worked flawlessly. The repair was much simpler and cheaper than initially expected, costing only 95€ to fix a faulty cable connection in the steering system. The symptoms you describe with the loose steering column when turning left should definitely be checked. While my issue was purely electrical, mechanical problems with the steering components can develop if left unaddressed. The electric steering system relies on precise signals between components, so even minor connection issues can cause serious handling problems. The mechanic also explained that these steering systems rarely need hydraulic fluid or pressure hose replacements since they are fully electric. Most issues stem from electrical connections or the control module itself. My suggestion would be to have it checked soon. The repair might be as straightforward as mine was. The important thing is preventing any additional wear on the steering components while the system isnt functioning properly.

Thanks for the input. I decided to get it checked since the steering was becoming increasingly unsafe. Took it to a certified Smart mechanic yesterday who diagnosed the problem quickly. Turns out my steering column had a worn electrical connection, just like you mentioned. The mechanic found corrosion on several wiring points which was causing the erratic steering behavior. Total repair came to 120€ including parts and labor, plus a wheel alignment. The steering feels completely normal now, no more shaking or heaviness. The warning light is gone and the electric steering works perfectly again. Such a relief to have it fixed, especially since I was worried it might need the entire steering system replaced. Really glad I got it sorted before any permanent damage occurred. The mechanic said catching these electrical issues early prevents more expensive repairs down the road. Definitely worth the investment for safe handling and peace of mind.