# Other power steering options



## PatricioIN (Jun 13, 2008)

Toyota Yaris and (I believe) all Scions have EPS (electric power steering) as well.


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## booksix (Aug 26, 2008)

The nice thing about the MR2 pump is you use stock steering components which retain the proper steering geometry. It is never as simple as just swapping in an electric rack, etc... Steering systems are very touchy and must be designed for the car. This idea could cost some safety points. Of course, if you have the know how to modify the system it would be a worth while project. IMHO, save your labor time (my hours are worth more than that, I'll just get an mr2 pump) and know it's setup right


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## PatricioIN (Jun 13, 2008)

booksix said:


> The nice thing about the MR2 pump is you use stock steering components which retain the proper steering geometry. It is never as simple as just swapping in an electric rack, etc... Steering systems are very touchy and must be designed for the car. This idea could cost some safety points. Of course, if you have the know how to modify the system it would be a worth while project. IMHO, save your labor time (my hours are worth more than that, I'll just get an mr2 pump) and know it's setup right


 I would agree that the mr2 pump is about the easiest way to go. I had to have one pressure line made for a $60. I reused the oem fitting that screws into the rack.


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## Qer (May 7, 2008)

booksix said:


> The nice thing about the MR2 pump is you use stock steering components which retain the proper steering geometry. It is never as simple as just swapping in an electric rack, etc...


Also, I think it's rather hard to get it typed in Europe due to very strict safety and environmental laws. The general rule is that you can't change one single bit on a car, for example it's literally impossible to change engine in a car if you don't get a perfect match due to environmental laws. However replacing it with an electric motor is allowed (since it's an obvious environmental bonus) but only if the power isn't more than +20%, the torque isn't more than +10% and the weight per axis and total isn't exceeded. That last rule plus the climate in Sweden has actually more or less made me decide to skip lead, collect some more money and go LiFePO4 instead.

But I digress, what I was coming to is that changing the steering column probably will take some care to get street legal, if it's even possible to change from original column at all. I already know you can't replace for example a power steering with a non power steering even if the model comes with both, if the car's typed with power steering it has to have power steering, period. That's why I think that replacing the steering column might also be totally out of the question in Europe.

Unless, of course, you rebuild your car so much that it's considered a custom made car rather than a modified car. Then there's a complete different set of laws and rules to comply and they give much more head room for mad ideas...


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## EV-propulsion.com (Jun 1, 2009)

I would like to suggest an easier way for a power stering pump. After many years of conversions, I have found that the stock P/S pump driven by the front motor shaft works surprisingly well. I have done fords, gm, chrysler, and mazda with P/S and this has worked fine. 
The amount of motor rpm needed to build up pressure for assist is less than 50 rpm. Prety much as soon as the motor starts turning you have assist. Everyone that has seen this on my conversions are surprised.Yes this will work for parallel parking once you start to move. Yes, you cannot have assist just sitting in one spot unless you spin the motor slightly (but you shouldn't be steering without moving anyhow)
I would suggest that anyone with a power steering donor try it this way before spending alot of time and money on electrical assist that more than likely would not be needed, and adding a drive pulley and bracket is not all that difficult on most conversions.
Oh, and yes automatic transmissions work without an auxilliary pump also!
Mike
www.EV-propulsion.com


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## hk20000 (Aug 5, 2010)

Hey guys new to the forums and this is my first post, so bear with me.

I don't own a EV but I am looking into operating a EPS in my 25 year old Toyota seeing how it was done in Japan:

















It runs an unknown Toyota pump in their "eco" AE86 which is what I'm trying to mimic on the other side of the Pacific. From the image it looks like it's either a Prius system or a Yaris system (with the ECU visible on the 1st picture up the column)

Since the AE86 itself does not have CANBUS or OBD2 I am wondering if the unit is operating without a known signal from the ECU?

From the Yaris wiring diagram there's the 12V power wire (60A) and then there's IGN power wire, speedometer signal (from gauge cluster) but the most worrying part is the CANBUS connection.

I also own a 2010 Nissan Cube but if I turn the key to ON without starting the engine the EPS on it does not assist my steering in anyway, knowing that the engine is not running. 

But there has to be someway to trick the ECU into thinking my car is running....? I need to fake a canbus signal somehow?

And to further complicate the problem, the car I drive now has an oh so environmentally friendly LEV S2000 motor and control unit in it, since the S2000 itself also comes with a EPS, I'm starting to wonder what will happen if I tap the signal from the EPS ECU to the main engine ECM? the CANBUS is just 2 wires of H and L right? How likely is it that I can just "steal" the RPM signal from the system and let the EPS ECU understand that the engine is now running (if the EPS is designed to not assist at 0RPM)

If not, is there anyway to fake a Toyota RPM signal into the thing?

Help is much appreciated, I have already shoved a Yaris EPS into the Corolla and it fits like a dream - but I don't know if it's going to work at all....


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## hk20000 (Aug 5, 2010)

no takers? I thought someone would have tried fitting this compact EPS system onto their car already? 

The whole system costs under $200 at your local junkyard and if this works without CAN signal or if we can simulate CAN signal this would be beneficial to everyone building a EV I think?


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## hk20000 (Aug 5, 2010)

hey guys so I hooked the whole thing up and it works perfectly.

But you don't like to chime in on this so.....figure this out yourself.


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## EVfun (Mar 14, 2010)

hk20000 said:


> hey guys so I hooked the whole thing up and it works perfectly.
> 
> But you don't like to chime in on this so.....figure this out yourself.


Good grief, angry because no one replied within 12 hours? It's not like hundreds of people are converting late model cars with power steering just today.

What wires did you need to hook up to use the Yaris power steering. 60 amp power and IGN 12 volts, along with ground, seem pretty obvious. Did you need any CAN signal or motor rpm signal?


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## Rum Runner (Oct 26, 2009)

I would like to keep power steering, but some of those choices I see here are outside of my range.

Has anyone hooked the power steering pump to a 12v motor?
I have a strong 12v motor that will turn the pump. I am not sure how much more force is needed when the pump is under a full load.

The motor and pump does not need to run all the time. I really don't need the power steering while driving straight down the road. 

I was thinking that if I mounted a proximity switch on the steering .
shaft, it would allow the motor to remain off during minor steering corrections and turn on for the more complicated maneuvers.
Maybe a pressure switch inside the steering box could activate the pump.

Would like to know because I really want to keep the power steering.


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## ZEVUtah (Apr 10, 2008)

Rum Runner said:


> I was thinking that if I mounted a proximity switch on the steering .
> shaft, it would allow the motor to remain off during minor steering corrections and turn on for the more complicated maneuvers.
> Maybe a pressure switch inside the steering box could activate the pump.


I was just reading about another car where this has idea has been used. You might want to find out more details from this builder. 

http://www.evalbum.com/3189

KJD


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## Rum Runner (Oct 26, 2009)

Thanks for the links. They were great. Lots more information to soak up.... Really like your solar set up also.


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## rod19033 (Nov 24, 2021)

Hi All
After quite a bit of time I figured out the can commands to enable a dodge/jeep EHPS. (charger/Challenger/Cherokee etc)
message if you need info, code/ schematics


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## remy_martian (Feb 4, 2019)

Post them for everyone here now. Or do you want to get hounded for eternity with the same request hundreds of times over a decade or two?

Your work may also get leveraged into circuit boards, etc if more eyes are on it.


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## DIGGER11 (Mar 16, 2010)

It took you over 11 years ?


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## rod19033 (Nov 24, 2021)

rod19033 said:


> Hi All
> After quite a bit of time I figured out the can commands to enable a dodge/jeep EHPS. (charger/Challenger/Cherokee etc)
> message if you need info, code/ schematics


Still a work in progress but using a atmega328 mcp2551 mcp2515 and a handful of passive
Basically connect the 2 main power wires connect the can controller to the can transceiver
Connect the center wire on the pump to 12v+ can_h and can_l
Send 0x308 0x54 0x01 0x40 0x00 0x00 0x00 0x00 0x00 and the pump will start. I believe it's running at about 80%
Still looking for the commands to control the speed.. if anyone has a 2011-15 dodge or jeep with the EPS if you could log the can data at highway speeds for a few seconds probably can solve that and make it controllable with vehicle speed
I'll try to follow up with schematics and arduino code if anyone is interested.
😁


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## remy_martian (Feb 4, 2019)

Nicely done. 

Suggest you start a thread and put everything in one place vs burying it in the clutter of this thread.


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## rod19033 (Nov 24, 2021)

will do remy, I'll put together some better documentation


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## rod19033 (Nov 24, 2021)

remy_martian said:


> Nicely done.
> 
> Suggest you start a thread and put everything in one place vs burying it in the clutter of this thread.











Dodge/Chrysler/Jeep EPS Pump


Dodge/Chrysler/Jeep EPS Pump Still a work in progress but I am using a atmega328 mcp2551 mcp2515 and a handful of passive Basically connect the 2 main power wires to fused battery voltage connect the CAN lines to pin 1 and 3 on the pumpr Connect the center wire on the pump to switched...




www.diyelectriccar.com


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## remy_martian (Feb 4, 2019)

It disappeared


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