Steering: Description and Operation: Overview

Power Steering


The vehicle is fitted with EPS (electric power steering), provided by a ZF Servolectric(R) steering gear unit with variable ratio, rack and pinion steering and speed sensitive power assistance. Power assistance is from an electric motor attached to the steering gear.
The steering gear also incorporates:
- A power steering control module, on the end of the electric motor.
- A reduction gear.
- A torque sensor on the gear mechanism.
Power assistance is controlled by the power steering control module, which uses the electric motor to apply an axial force on the steering rack via the reduction gear. The level of power assistance depends on the steering torque applied with the steering wheel, vehicle speed and terrain response mode selected. The power steering control module also uses the electric motor to provide the following assistance features:
- Pull drift compensation.
- Assistance changes during Eco Stop/Start functions.
- Assistance reduction if system overheats.
- Assistance reduction if low or high voltage.
- Assistance reduction for system stability optimization.
- Soft end stops.
- Park assist support (where fitted). For additional information, refer to Parking Aid Locations