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D.I.Y Electronic Power Steering

179K views 269 replies 80 participants last post by  Reamos DC5 
#1 · (Edited by Moderator)
So I finally finished converting my car to electronic Power Steering the other day and I made a small DIY for you. Let me just say this is an easy swap and most people are worried about it but after doing it I realized just how easy it is.

This is also an updated version with new Info than Erik's local DIY and this version works for 05 PEOPLE with NO Dakota digital box!!!!


First here are all of our parts!

Rack and Pinion
Tie Rod Ends
Brain Box
Wiring Harness
EP3 Brackets



First thing first we need to rip out the Hydraulic Power Steering lines and pump. I already did that as I'm running no P/S



So first lets unbolt the wheels and un bolt the tie rod ends


next for more clearance, I took out this lower bar


then unbolted the PS rack from the RSX brackets






Then go inside the car and unbolt the 10mm bolts holding on the joint on the steering shaft


Now unbolt the brackets from the frame and rip out the rack and pinion



Now let's compare the RSX and EP3 racks



HERE IS THE NEW INFORMATION~!!!

The inner tie rod ends are the same!! There is no need to swap the entire tie rod assembly like everyone else!!!! Only the outer tie rod ends are different and need swapping! So take a wrench and swap them out!





Here you can see the difference in the rsx and ep3 tie rod ends. The RSX is much thicker going into the strut assembly.


Now let's slap in the new EP3 rack and pinion and bolt it up to the new EP3 Brackets you also needed.





So now your rack is in and it's time to do the wiring... There is not much to it!
 
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#2 · (Edited)
So first thing I did was go inside the car and run the new wiring harness threw the location of the stock wiring harness. Under the carpet footboard for the gas pedal. Then pulled the wire out into the engine bay and up to the eps rack








Now I mounted my box and plugged it in



But we need power! For this I made a custom plug into the factory plug and ran a power wire out the fender to my fuse box. You can either go to the fuse box like I did or go to the battery like Loza did. I went to the fuse box because I relocated both box and battery and my box was closer!





and here is where I went into the fuse box. I decided to add a inline fuse. I used the power source on the left which is coming straight from the batter. So if you wanted you go also go straight to the battery instead of the fuse box. But for me my fuse box is closer than my battery.



I then cut a small opening for the cable on the lid
 
#3 · (Edited)
Now onto the ECU wiring! You only need to add three wires to the new EPS. Engine RPM, Vehicle Speed, and constant power!

I tapped into the hondata jumper harness using three different colored wires to identify each one!


here I tap into the lines




Blue White goes to pin A18 VSS sensor (vehicle speed sensor located in tranny)
Solid Blue goes to E26 NEP (Engine RPM or Engine Speed Sensor)
Yel goes to pin E9 IGN power (this is IGN to let the BCU know when engine is running)

02-06 ECU diagrams are the same. refer to Hondata for ECU pin out.
http://www.hondata.com/help/kmanager/
Reference > ECU connectors

Connector A (2p)
THICK blue/white is +power for EPS system 60A fused
THICK BLACK is - PG Power ground to chassis
 
#7 ·
being that I have one bum arm and was doing it by myself I took a break here and there. But it took maybe 2-3 hours tops. Not long at all.

damn dude...nice work!!...sweet DIY!!...where did you pick up the EPS? and whats the best place to look??
I picked up everything from a local salvage yard. I would start buy finding a nice yard and calling them up
 
#11 ·
So to answer your question Zurmagus

There are three wires from the EPS harness you need to tap into the RSX ECU. The colors will match for two of them. But obviously from my photos I taped into the jumper harness not the actual harness. The two wires in the harness are VSS and engine RPM. Blue wire and blue with white wire. The hitrd wire from the EPS is just constant power I went into the fuse box for that.

Pros and Cons:

Pros - my steering is fast as hell and extremely sensitive! You can make the sharpest turns and fastest on ramps with just a finger its so awesome...

Cons - Power Steering doesn't kick in right away it needs to readjust for the different VSS. So once I hit like 5-10mph it starts working. So if you need to turn sharp right away when turning on your car no P/S. (AT LEAST FOR ME) But EPS rack with no PS is a shit ton easier to turn the Hydraulic rack with no PS. Also another con is EPS is speed sensitive. With the different EPS the PS is only on or off for the 05 guys. But I have no complaints and love it!
 
#31 ·
plannin on this mod.. but your ecu wiring is a little.. well very vauge...
can you dumb it down a bit...
plus all blue wires dont help lol.. must be a bitch sittin there with a pinout guide vs lookin for colour codes
 
#32 ·
I have my ECU actually so I will definitely be able to take some better photos for you... I actually uploaded the pictures and said oh wtf... but no one has asked or said anything yet. Your request will be filled shortly:thumbsup:
 
#34 ·
Very nice man.. I'm actually just pulling mine out sending it to rebuild and put it back in.. I have play on the steering wheel n pull to the right so I think it's the rack. This will save me some $ and a BIG head ache from trying to do it without any steps or pictures. Thanks alot.
 
#35 ·
why

OK help me out here.

All the professional car reviewers praised our car's powesr steering system and most hate all electric power steering for vagueness, lack of proper on-center feel, lack of communication of road surface, etc.

EPS's sole function is to increase MPG. So why reverse engineer the inferior system from the superior system?Did you need to get rid of the power steering pump to make room for a supercharger pulley or something?
 
#36 ·
OK help me out here.

All the professional car reviewers praised our car's powesr steering system and most hate all electric power steering for vagueness, lack of proper on-center feel, lack of communication of road surface, etc.

EPS's sole function is to increase MPG. So why reverse engineer the inferior system from the superior system?Did you need to get rid of the power steering pump to make room for a supercharger pulley or something?

Yes being supercharged I wanted to run the stock belt tensioner which is the best. But runing that with the power steering is very difficult. The easy solution is to run the EPS. But I also did it to help with my wire tuck. And truthfully I think the EPS feels a lot better than the hydraulic in terms of quickness and reaction. But I agree it is harder to feel the road.
 
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