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Chassis technology

What Is Steer-by-Wire?

Steer-by-wire replaces the traditional fixed mechanical steering connection with sensors, electronic control, actuators and software. The driver still turns a steering control, but the requested steering angle is transmitted electronically.

Updated: October 9, 2026CarGlossary emerging-term series
Simple definition

Steer-by-wire is a steering system in which the driver's steering input is transmitted electronically rather than through a fixed mechanical connection between the steering wheel and road wheels.

How steer-by-wire works

A steering-wheel actuator measures the driver’s input and can generate feedback at the wheel. A separate road-wheel actuator creates the steering force at the axle. ZF’s production system uses redundant sensing and actuation strategies because steering is safety-critical.

Why remove the mechanical connection?

  • Variable steering ratio can be controlled in software.
  • Steering feel can be tuned electronically.
  • Packaging freedom can support new cockpit designs.
  • It integrates naturally with advanced assistance and automated-driving functions.

Is steer-by-wire actually in production?

Yes. ZF began series production for the NIO ET9 and announced a Mercedes-Benz program scheduled for 2026, alongside additional Chinese customer programs. That makes steer-by-wire a current production technology rather than only a concept-car feature.

Mercedes-Benz EQS: available to order in October 2026

Mercedes-Benz confirmed on October 6, 2026 that its EQS Saloon steer-by-wire option is available to order in EQS markets worldwide. In Germany, the option starts at €2,975 including VAT (€2,500 excluding VAT) and includes rear-axle steering of up to 10 degrees and a redesigned steering wheel. Availability, equipment and prices vary by market; this German price is not a worldwide price. This is a confirmed series-production application, not a concept or a future promise.

Mercedes says the system replaces the mechanical steering connection with electronic transmission of driver inputs. The vehicle's redundant safety design remains critical.

What happens if electronics fail?

A production steer-by-wire system needs redundancy, fault detection, power-supply resilience and a defined safe response. Removing the mechanical link does not remove the safety requirement; it makes robust electronic and software architecture more important.

Brake-by-WireVehicle domain controllerSoftware-Defined VehicleE/E architectureADASAutomatic emergency braking

Sources

CarGlossary note:

Automotive terminology evolves quickly. We separate established standards from manufacturer-specific names and update pages as technologies move into production.