Toyota Electric Power Steering (EPS) Conversion

You may have already seen the GM (Saturn Vue) electric power steering swap information posted here. While looking up information on electric steering, I found some information that I think we need to share and preserve here.

Most Japanese branded cars and SUV’s with electric steering works in Fail-Safe mode if the control unit (ECU) is disconnected from CAN BUS. The effort in fail-safe mode feels just right; not too much and not too little. Just like hydraulic steering, if the Electric Assisted Steering completely fails, the steering is back to completely manual mode maintaining car control.

The biggest advantage of using EPS from Toyota, Nissan and Kia/Hyundai is that the EPS works in fail-safe. The ECU for the column is mounted remotely and can be disconnected and removed. The EPS from Saturn Vue and Chevy Cobalt has the ECU that cannot be disconnected and must have the wires extended for remote mount. More importantly, there is no fail-safe and a 3rd party eBay control module is needed in order for it to work. Additionally, people have reported that with the aftermarket control module, the Saturn (GM) EPS does not self center the steering wheel coming out of a turn. You have to make constant corrections.

Below is the list of cars that are known to have fail-safe electric steering. Only (3) wire connections; Ignition On, Power, and Ground to the Steering ECU. That’s it!

2004-2009 Toyota Prius
2009-2013 Toyota Corolla
2006-2011 Toyota Yaris – (With ABS)
2007-2009 Nissan Versa
2009-2012 Nissan Cube
2012-2014 Kia Soul

ECU Part Numbers:

2004-2009 Toyota Prius 89650-47102
2009-2013 Toyota Corolla 89650-02300
2006-2011 Toyota Yaris – (With ABS) 89650-52120 / 52050
2007-2009 Nissan Versa 28500-EM30A / 991-30303
2009-2012 Nissan Cube 28500-1FC0B / JL501-000932
2012-2014 Kia Soul B2563-99500 / 4PSG1312 / FPSG1312

The output shaft on Toyota is little larger than the rest and therefore the Borgeson 312500, 11/16 36 X 3/4 smooth bore weldable coupling should fit nicely. This coupler fits the others as well. The Kia EPS is the biggest and appears to be most heavy duty. The Prius & Corolla EPS are very easy to find at salvage yards so this is the best bet.

Notes:

As with any modification, there are risks. This page is intended to show how this modification has been performed. Use it at your own risk!

This modification was performed on a 1964 Ford Falcon. Hopefully there is enough information to help you with your own conversion.

General Information:

Wiring Diagrams:

Only 3 wires are needed. Power, Ground and Ignition On

The Upper Steering Shaft And Column Tube:

Lower Steering Shaft For Rack And Pinion Setup:

Converting Hydraulic Steering:

In order to convert my hydraulic power steering rack to manual, I took the valve out, removed the sleeve and tack welded the input shaft to the pinion shaft.