power steering

[cali yaris]

Does anyone know if the electronic power steering in the Yaris is connected to the main ECU?

I know it has its own relay and control unit, just wanting to know if it has any "relationship" with the ECU.

Thanks

[1NZYaris1]

It is connected to the can communication to the abs ecu and main ecm , according too pg 3 of PDF , Emailling PDF to you know.:thumbup:

[silver_echo]

hey if you are pulling it out, i am curious to know if it will fit my car...

[cali yaris]

pulling what out?

ray, my car doesn't have ABS, so that shouldn't matter. The main ECM part does seem to have killed it though. :frown:

[Loren]

Are you trying to pull the factory ECU and use alternate engine managment?

I don't think the PS cares if the engine is RUNNING or not, so you could leave the factory ECU to run the PS and gauges and everything else that it runs (modern ECU's are pretty pervasive), just disconnect it from the sensors on the engine that you need for your aftermarket ECU.

I'm basing this assumption on playing with hypermiling recently... if you turn the ignition off, the power steering goes away instantly (umff!). But, if you turn the ignition back to the "ON" position without restarting the ignition, the power steering comes back.

[CASTREX]

I thought that there was some variability on the power steering...

Like softer at low speeds and harder at higher speeds.... wouldn't something like this be controled by the ECU? :iono:

[cali yaris]

Oh I get it now. Yes, we pulled it - the ECU has been out for a while now. The dash gauges all work without it (speedo, fuel, etc). I didn't think about the power steering until yesterday when we were tuning it.

I think I'll just do without for now -- I am actually really liking the feel.

[Loren]

You might investigate fitting a manual rack. I have an old Tercel with a manual rack that drives just dandy. Something like that might fit.

[1NZYaris1]

pulling what out?

ray, my car doesn't have ABS, so that shouldn't matter. The main ECM part does seem to have killed it though. :frown:

Yeah i thought about that ,sorry, but theres a diagram further on that shows how it works with non abs cars , and it still runs via main ecu .
which also controls dash warnning lights for power steer failure.
looks like you need to send speed and rpm message to power steering ecu .
:thumbsup:

[schleppy]

This is somewhat on topic, but can you shut the OEM electric power steering off? Is there a fuse you can pull or a connector you could unplug? I'd be curious to see how it feels.

In my old Miata I disabled the power steering and I enjoyed the feel quite a bit (not as nice as a manual rack, but better than nothing).

Thoughts?

[Loren]

There is a PS fuse you can pull. I tried it. It sucks.

Really, it's not bad at speed, but way too hefty when making turns. You'd need really big arms to autocross with it that way!

[schleppy]

There is a PS fuse you can pull. I tried it. It sucks.

Really, it's not bad at speed, but way too hefty when making turns. You'd need really big arms to autocross with it that way!

Maybe I'll give it a go (though I do believe you). Did it throw a check engine light or anything?

[Loren]

I don't remember if it threw a CEL, I don't think so. This is one of the many things I posted about when I did it, but the info got lost when the forum got hacked. (and the admin had no backup)

[CTScott]

I don't remember if it threw a CEL, I don't think so. This is one of the many things I posted about when I did it, but the info got lost when the forum got hacked. (and the admin had no backup)

It won't throw a CEL. PS has its own ECU that reports its own DTC's to the techstream tool.

[cdydjded]

Does anyone know if the electronic power steering in the Yaris is connected to the main ECU?

I know it has its own relay and control unit, just wanting to know if it has any "relationship" with the ECU.

Thanks

The guy in PR with the 2ZZ swap had the same problem but was able to modify something to make the power steering work, I will try to get in touch with him to see what he did

[severous01]

you're wanting to take something that's electric and has no draw on the engine.....and put a pump that's engine drawn onto the car??? and a rack/pinion setup?

makes no sense to me. unless you're doing hydro-boost braking and need PS to get it....even then you may as well run an electric vacuum pump...

makes no sense to me, it doesnt draw any power from engine and it's not a performance issue unless you like building your jackoff muscles....for you single guys out there....i'd leave it alone and get a bigger battery if you're wanting to buy parts for nothing...a PS rack and install could run you thousands...buy a nos kit with your extra $$$

[Shroomster]

you're wanting to take something that's electric and has no draw on the engine.....and put a pump that's engine drawn onto the car??? and a rack/pinion setup?

makes no sense to me. unless you're doing hydro-boost braking and need PS to get it....even then you may as well run an electric vacuum pump...

makes no sense to me, it doesnt draw any power from engine and it's not a performance issue unless you like building your jackoff muscles....for you single guys out there....i'd leave it alone and get a bigger battery if you're wanting to buy parts for nothing...a PS rack and install could run you thousands...buy a nos kit with your extra $$$

someone's stick went missing...check your ass....

just like your comment, mine added nothing to the relevant conversation....

[schleppy]

makes no sense to me, it doesnt draw any power from engine and it's not a performance issue unless you like building your jackoff muscles....for you single guys out there....i'd leave it alone and get a bigger battery if you're wanting to buy parts for nothing...a PS rack and install could run you thousands...buy a nos kit with your extra $$$

Some people don't enjoy the feel of an over-assisted power steering system (*cough* the yaris system *cough*). It has nothing to do with machismo. Drive a car or two with a proper manual steering rack (or nicely weighted power steering setup) and you'll understand.

[jimek]

where is the fuse to pull to get rid of the power steering at?
and can i just put it back in later and have it work like normal again?

[Dadombomb15]

fuse is under the hood in the fuse box next to the battery
on the inside of the top of the fuse box, there's a diagram.
just removed mine tonight, i really like the feel without the PS. It's a lot tighter than you would expect. my family is riddled with classic cars without power steering, and i really like the feel of that, but this is a little tighter than that. I think I'm going to run without it for a while though :]

[Dadombomb15]

posted from a thread on microimage forums

http://i270.photobucket.com/albums/jj115/jimroadmaster/IMG_0598.jpg
fuse box..

http://i270.photobucket.com/albums/jj115/jimroadmaster/IMG_0600.jpg
fuse box label..

http://i270.photobucket.com/albums/jj115/jimroadmaster/IMG_0601.jpg

this is with the fuse already removed. and yes you can just pop it back in when you want to use it again. be careful, because when i pulled mine out, it fell into the engine bay and rested on the bodykit JUST out of reach, took a lot of maneuvering and long sticks to get it to a point where I could get it.

[schleppy]

I gave this a try last night (pulled the fuse before I left work) and drove home. My god it was awful.

I've driven quite a few cars that didn't have power steering (or it was disabled) and they felt great. The Yaris felt so horrible. The wheel was incredibly hard to turn at all speeds (even on the highway when it should be easier). Needless to say I re-enabled the power steering when I got home.

It's a shame too, I bet the Yaris would benefit greatly from a nice, quick ratio, manual steering rack...

[IllusionX]

i guess because the electric motor is suck there when you have it disabled... hence the very hard to turn at all speed.

[schleppy]

i guess because the electric motor is suck there when you have it disabled... hence the very hard to turn at all speed.

I guess so. You would think they would have designed it to "loosen up" a bit if the power cuts out to the steering motor. Oh well.

[CTScott]

You might want to try unplugging the cables from the power steering ECU (which is under the dash above the steering wheel). It may be placing a load across the motor leads when unpowered, which would cause regenerative braking of the motor (which means the quicker you move the motor the more it resists). Unplugging the connectors would disconnect the motor from the unpowered control circuitry to ensure that there is no load.

[jimek]

fuse is under the hood in the fuse box next to the battery
on the inside of the top of the fuse box, there's a diagram.
just removed mine tonight, i really like the feel without the PS. It's a lot tighter than you would expect. my family is riddled with classic cars without power steering, and i really like the feel of that, but this is a little tighter than that. I think I'm going to run without it for a while though :]

i know that now, that was me on the micro image forum hence the same username.. and those are the pics i took haha

[Dadombomb15]

i know that now, that was me on the micro image forum hence the same username.. and those are the pics i took haha

hence why I was sure to give credit where it was due, sorry I didn't have your name posted in my quote, couldn't remember it. If it came across as if i was taking credit for it, my apologies haha that was a really helpful post :]

edit: and after re-reading a second time what you said, my bad, i didn't recognize it was the same username haha
also, if anyone is wondering if it will show anything on the hud, a red P/S shows up. and when i turn the car on, i notice a few clicking noises like it's trying to switch it on? does anyone else notice that when the fuse is out?

[jimek]

i didnt notice any clicking ill check tonight though