# SSP 259 EPHS – Electrically Powered Hydraulic Steering

> VW Self-Study Programme 259: design and function of the electro-hydraulic power steering (EPHS) of the VW Polo 6R, TRW and KOYO versions, with service notes.

- Web page: https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/
- Original document (PDF): https://cdn.polo.blue/files/ssp-259-electro-hydraulic-power-steering.pdf
- Whole programme in one file: https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/full.md

![Overview (259\_033)](https://catalog.polo.blue/instructions/ssp-259/5c5c3e677e0b0094.webp)

The EPHS = Electrically Powered Hydraulic Steering is familiar from the Lupo FSI. This system is supplied by TRW and by KOYO.

The new steering system offers a wide range of advantages while at the same time retaining the excellent steering properties of the conventional hydraulic power-assisted steering.

Advantages of the EPHS:

- Improvement in comfort, easy to operate when parking, but steering firm at high speeds (safety factor).
- Fuel savings, as the energy consumption is based on demand – irrespective of the operating state of the internal combustion engine.

> **Note**
>
> The Self-Study Programme describes the design and function of new developments! The contents are not updated.
>
> Please always refer to the relevant service literature for up-to-date inspection, adjustment and repair instructions.

## Chapters

- [Introduction](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/introduction/index.md): How the electro-hydraulic power steering differs from conventional power steering: TRW and KOYO versions, warning lamp K92, sensors G250, G85, unit J500.
- [System Overview](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/system-overview/index.md): Schematic diagram of the EPHS and its advantages: energy savings of up to 85 % and about 0.2 l/100 km less fuel.
- [Design and Function](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/design-and-function/index.md): Engine pump assembly, control unit J500, the TRW capacitive and KOYO Hall sensors G250, steering angle sender G85, restart protection, hydraulic control unit.
- [Function Diagram](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/function-diagram/index.md): Function diagram of the EPHS with control units J500, J220, J285, J519 and J533, sensors G250 and G22, warning lamp K92 and the CAN lines.
- [Service](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/service/index.md): Checking the hydraulic fluid level of TRW and KOYO steering, warning lamp K92, self-diagnosis with address word 44, recognising the steering version.
- [Test Your Knowledge](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/test-your-knowledge/index.md): Nine questions on the EPHS with the answers: pump, input signals, TRW and KOYO, warning lamp K92, restart protection, Hall sensor.
- [Subject Index](https://catalog.polo.blue/self-study/ssp-259-electro-hydraulic-power-steering/subject-index/index.md): Glossary: map, calibration, capacitor and capacitance, semiconductor, CAN databus, gateway and the Hall effect.