While muscle power was still required for steering until the 1990s, technical development in this area has since accelerated enormously. The traditional hydraulic power steering systems that dominated in the past are being replaced by electromechanical steering across more vehicle classes. Rear axle steering systems emerge as a new technical trend. As an automotive supplier, ZF plays a leading role in all these developments and also makes its expertise available to the aftermarket. The new technology holds challenges in store for workshops.
 

With numerous benefits over and above its predecessor, EPS has become the industry standard in vehicles rolling off the production line. But in the meantime, power steering systems are no longer solely responsible for comfort, but are an integral part of the driving safety concept and an essential prerequisite for assisted and, in the future, automated driving functions.

These functions are only possible with Electric Power Steering systems that can generate steering torque independently of the driver. And this design has another advantage: it saves energy because it only requires electricity when a steering movement is actually being performed. For these two reasons, electromechanical power steering has now established itself in virtually all passenger car segments. Even heavy SUVs and sedans as well as vans are increasingly equipped with this steering design.

Automotive workshops therefore need more and more electronic expertise to work on steering systems. This already starts with troubleshooting. After all, steering failure can also be caused by faults in other vehicle components, such as fluctuations in the power supply. Automotive mechatronics technicians should therefore check the electrical connections, ground points, battery and alternator power before replacing the steering gear. Sensors or control units on the vehicle that communicate with the steering system can also be the root cause of faults or failures. So, these should also be checked, especially if the fault diagnosis is not clear.

Various work steps necessary after the steering gear installation

Incidentally, repairs to the steering gear itself are not possible; it has to be completely replaced. It is important to keep an eye on the large number of possible variants. There are also different software versions and maps for each vehicle variant. Therefore, depending on the vehicle architecture, the following work steps may still be necessary after mechanical installation:

Teach-in/adjustment of sensors
Registration of the steering system in the different control units of the vehicle
Coding of corresponding equipment variants
Selection of the steering assistance map
Installation or updating of the software of the steering system or also of other vehicle control units

Growing range of remanufactured steering systems

ZF Aftermarket provides its workshop partners with all the necessary technical information for troubleshooting and replacing electric power steering systems on its Internet portal aftermarket.zf.com. In addition, the company supplies a wide range of spare parts under its TRW brand. This also includes remanufactured steering gears, which workshops can use to make their customers repair offers in line with the current value. These have been industrially remanufactured at ZF's own remanufacturing plant according to OE guidelines and correspond to new parts in terms of performance and quality.

As of now, steering gears are available for the following high-volume vehicle models, among others:
• Audi A3
• Skoda Octavia
• Volkswagen Golf V
• Volkswagen Passat

Customers can access the complete portfolio of available steering gears quickly and easily via the online catalog at aftermarket.zf.com.

Rear-axle steering systems are the next trend

Electromechanical steering systems are no longer only found on the front axle. More and more vehicles are also equipped with rear-axle steering. ZF, for example, has already produced more than one million units of its AKC system (Active Kinematics Control). Rear-axle steering systems become necessary above all for heavy vehicles or those with a particularly long wheelbase in order to ensure the driving dynamics desired by the customer and to improve the handling of the car, especially on narrow roads.