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As a manufacturer, we want to provide you with the products you need to grow your business. As a business partner, we want you to fully understand the product you are selling – and to be confident in passing that message on.
Customer Focussed
This feature examines TRW’s range of EPHS pumps. It looks at product differences and gives you some technical background and knowledge to enable you – and your customers – to get the best from the systems.
TRW currently offers three main types of electrically powered steering pumps to the European independent aftermarket.
- Electric steering pump without steering angle management
- Electric steering pump with steering angle management FULLY programmed
- Electric pump with steering angle management PARTIALLY programmed.
TRW - The Pedigree Behind the Power
As a leading designer, integrator and producer of all major steering technologies, TRW Automotive provides systems that enhance vehicle control, increase fuel savings and improve performance precision. With decades of expertise and millions of systems on the road, TRW delivers true steering solutions.
TRW offers the largest selection of Electrically Assisted Steering (EAS) technologies in the world, and was first-to-market with Electrically Powered Hydraulic Steering systems for Europe.
TRW’s EPS technologies are a key enabler for advanced comfort and safety systems, such as Park Assist, Steering Torque Control and Lane Keeping Systems.
TRW’s expertise in the field has led it to offer three key types of EAS systems: Column Drive Electrically Powered Steering (EPS), Rack Drive EPS and Electrically Powered Hydraulic Steering (EPHS).
Electric steering pump without steering angle management
This is the most efficient way of using an electric steering pump. It has a minimum of three connectors – two for power supply and one to give the pump information about how the engine is running. As an optional extra, an additional connector would give the steering pump information about the speed at which the vehicle is travelling, enabling speed related steering assistance. This pump ONLY works if the engine is running and with no connection to a steering angle sensor it must operate without this support.
Top Tip
Any problems with this steering pump are likely to be simple to deal with. Check the condition of the battery and the alternator and pay particular attention to the electrical vehicle connections. |
Electric steering pump with steering angle management FULLY programmed
This system is developed from the electric steering pump WITHOUT a steering angle sensor. The two big differences are:
- If the vehicle has a steering angle sensor, this pump can be managed through it and the vehicle benefits from added steering support
- This pump can be fully integrated into the vehicle’s CAN-Bus system so it can communicate with the vehicle’s other electric control units (ECU’s)
As an additional feature, the pump can be fitted with an ‘Eco Modus’ which turns off the pump if no steering support is needed.
Top Tip
Because of the high dependence of the steering angle sensor and the CAN-Bus system, the fault diagnostics can be complex.
If you experience any problems, check the alternator and battery, steering angle sensor, control units and electrical connections. Also check that you have the latest versions of any control unit software. |
Electric steering pump with steering angle PARTIALLY programmed
The only difference between this system and the pump described above is in the hardware and software of the ECU of the steering pump.
With this system, the electric steering pump can only be logged in and adapted to the vehicle by going through the specific vehicle manufacturers diagnostic system. This means the steering is more linked into the vehicle's electronics.