Check Out my New Servotronic Mod (PowerAssist Disable Mod)...

[Eddie Man]

Well first of all, just a recap of my earlier mod...

I know when I had my A6/2.7t, removing the Servotronic Relay (for me, I retrofitted an In-Line Dash Mounted Switch) disabled the powersteering assist or boost at all times. For the A6, it proved to be invaluable for increased road feel and drivability for speeds above 15mph...
As for powersteering assist while parking, one just has to flip the retrofitted switch to re-activate the Servotronic.

I just completed the above mod on my S4...
I'm sure this applies to both B6 & B7 models.
I used a Tech Article in the A6 Electronics Section from AW >>> Modifying the Servtronic Steering Boost Relay to Tighten Steering
And also this write-up in the MJB Motorsport Site as resources >>> Servotronic

Mod Time = 30 min.
Tools Required:
1. Wire Stripper
2. Socket Set
3. Drill with 3/4" spade bit
Parts Required:
1. (2) Wire Nuts (smallest guage available); Soldering would be best though in lieu of nuts.
2. Electrical Tape
3. On/Off Rocker Switch (Radio Shack #275-693)
4. 2 wire cord (light guage, my guess is that 20 or 22 ga is fine).
5. (2) Spade Connectors

Well anyways, here's what I did:
1. Locate Servotronic Relay adjacent to the Fuse Area


2. Locate 3 screws that secure the driver's side dash panel. 2 at footwell and 1 inside fuse box area. Remove dash panel. Sorry no pics :(

3. Locate 2 screws that secure fuse box to fuse box bracket. Remove fuse box and push aside for clearance to relay boards.

4. Locate relay boards & 2 mounting nuts.


5. Pull Servotronic Relay Out, remove 2 mounting nuts & remove lower relay board and push aside to access Servotronic Relay Board.



6. Remove Servotronic Relay Board and push aside to access the rear of the board.


7. Pop-Out the Servotronic Relay Harness to aid working on wires.


8. Locate BLACK wire behind harness.


9. Snip Wires and wire nut the ends to a 2-wire cord & tape connections to prevent wire nuts coming loose. For this step, soldering is best but the space to work in is very tight, so this is the next best thing, IMO.


10. Carefully re-assemble (#7, 6, 5, 4 & 3 above in that order).

11. Locate Switch to your liking. I located my non-OEM Switch in an inconspicuous location (not to clash w/OEM Switches) in the Owner's Manual Slot Area. Drill hole in lower dash panel.


12. Strip free-end of 2 wire cord and secure spade connectors. Connect spade connectors to mounted switch.


13. Add some electrical tape to the connectors for problem free electrical current.

14. Finished Servotronic Switch (on left). BTW, the switch on the right is my On/Off Switch for my Lidetek LE-30.


15. Carefully re-assemble (#2 above).

16. Done :)

Observations:
I test drove it this evening and all I got to say is WOW.
A completely new driving experience w/no power assist. Pretty tight steering as it feels much better (at least for me) to the touch.
Best of all, I can go back to stock in a flip of a switch. It's definetly needed when parking.

Well I hope this helps whomever wants to give this Mod a whirl.

[S4J]

Nice write-up once again Eddie. Hey, what's the other switch for? I searched your mods but didn't see it?
Just wondering...Steve

[mercury26]

Ejector seat and oil slick spray out the back. :)

Cheers,

Chuck

[Eddie Man]

Nice write-up once again Eddie. Hey, what's the other switch for? I searched your mods but didn't see it?
Just wondering...Steve

Thanks...
It's for my Lidetek LE-30 (laser jammer).

[scoobycarolan]

Eddieman~ you rule.

[UberDave]

That's hard core, nice job.

[Storm33]

Very cool! Wish I had the cojones to mess with stuff like this.

[littleredwagen]

i did this mod on an allroad what difference it makes

[Cosworth]

I am a little confused on the black wire, just to clarify is that the only wire that is cut? & where is it wired to... Just the on off switch? Maybe I missed something thanks!!!!

Knick

[JMG]

I'm not too knowledgeable, so forgive the noob question:

Does adaptive power steering allow for the steering to be very light at low speed, and unassisted at higher speeds? That is different than power steering is it not?

Is there a way to disable adaptive power steering but keep power steering so when you are parking you don't have to strain yourself?

I know the A4s have a similar mod, but they just pull a fuse I believe, but I could be wrong. Is this the same thing but with a switch?

[Eddie Man]

I am a little confused on the black wire, just to clarify is that the only wire that is cut? & where is it wired to... Just the on off switch? Maybe I missed something thanks!!!!

Knick

Yes, just the black wire...
The black wire, if disconnected will disable the Servotronic Function.
So basically, the switch acts as the enable/disable function for the Servotronic.
Hope that clears things up. :)

I'm not too knowledgeable, so forgive the noob question:

Does adaptive power steering allow for the steering to be very light at low speed, and unassisted at higher speeds? That is different than power steering is it not?

Is there a way to disable adaptive power steering but keep power steering so when you are parking you don't have to strain yourself?

I know the A4s have a similar mod, but they just pull a fuse I believe, but I could be wrong. Is this the same thing but with a switch?

Yes & Yes.
Yes, this mod is basically that and as when you park and need to go back to normal mode, one just flips the switch.
Yes. It's pretty tough to reinsert that module conveniently when you need it, hence the switch.

[wva s4]

I also did this mod to the old 2.7 A6 and loved it, but I have never noticed the S4 being as overboosted (for lack of a better word) at higher speeds like the A6. Maybe I will pull the relay to see how it feels? I remember my wife having trouble turning that boat in the driveway when I would forget to flip the switch. the switch is a must!!!

[jmarch]

So does this mod completely disable the power steering or simply eliminate the additional assist provided at low speeds?

TIA,
Joe

[Eddie Man]

So does this mod completely disable the power steering or simply eliminate the additional assist provided at low speeds?

TIA,
Joe

Just the additional assist at low speeds.

[ngng]

I like the switch idea

[jmarch]

Thanks Eddie.

[jimrobbington]

Badass Eddie, thanks. I hate the servotronic, but need it on 9 hour long drives. this is just what I needed. +1

[Eddie Man]

Badass Eddie, thanks. I hate the servotronic, but need it on 9 hour long drives. this is just what I needed. +1

Thanks and I'm happy to help.
And you are right, the switch comes in handy at those times when you crave that tight steering feel!

[minameismud]

is it ok for the ecu to switch this on & off while the engine is running?

[jimrobbington]

Thanks and I'm happy to help.
And you are right, the switch comes in handy at those times when you crave that tight steering feel!

I am currently trying to find a stock-looking button to do this mod, similar to this a3 button, but have had no luck!

[v_audi]

is it ok for the ecu to switch this on & off while the engine is running?

I'm curious about this as well. Anyone have any long-term feedback from using the switch. This is the only thing that is holding me back from installing it this way. Thanks.

[jimrobbington]

The OP has had this done for two years, with no problems thaT I can see. I'm sure he uses it everyday. He'll reply soon.

[Eddie Man]

I am currently trying to find a stock-looking button to do this mod, similar to this a3 button, but have had no luck!

I've been searching since 2003 (back when I still had my A4/3.0) and I too have had no luck.
What I have found is an OEM momentary switch like the one I use for my Remote V1 Mute Switch
The ones you've shown for the A3 are also momentary switches.
I guess, one could use anyone of these momentary switches and w/a series of relays, could accomplish what one would want.
But you know, simplicity is usually the safest bet.

I'm curious about this as well. Anyone have any long-term feedback from using the switch. This is the only thing that is holding me back from installing it this way. Thanks.

Yep...
jimrobbington is right.
I've had mine installed in my '03 A4/3.0 w/o any problems and I've had it installed after a few months of ownership (9/07) w/o any problems whatsoever.

[minameismud]

completed this mod this weekend, and it works great! kinda screwy turning it on & off while turning - not recommended. and to anyone looking to do this mod: USE WIRE NUTS! i tried crimp butt connectors and they kept falling off. i ended up having to solder an extension wire onto both ends to have enough for the wire nuts i eventually picked up.

anywho, thx for the DIY!

[v_audi]

jimrobbington is right.
I've had mine installed in my '03 A4/3.0 w/o any problems and I've had it installed after a few months of ownership (9/07) w/o any problems whatsoever.

Thanks. +1. I appreciate the info. and the DIY

[MonkeyBiz]

I am currently trying to find a stock-looking button to do this mod, similar to this a3 button, but have had no luck!

Could you install the "Funk" button...http://oemplus.com/index.php?main_pa...roducts_id=545...and wire it to that?

[jimrobbington]

Yes, theoretically, but the funk button is only a momentary switch meaning, it will only turn it off while it is pressed. Supposedly there is a series of relays you can make to turn it into an on/off switch, but I'm no electronics engineer. Also not a big fan of the funk button, and was looking for something different.

[felondnb]

I might have to give this a go... it would be great to have an OEM style switch though

[nvds4]

Awesome...easiest & best mod ever! Just what the Doc ordered. Much "meatier" feel. Now I don't feel like a granny after driving the S4, then the 335, back-to-back.

[Fox]

Thanks for the DIY!

Is there a way of installing the switch without cutting the black wire? I tried to pull out the wire after removing the top part of the socket but I couldn't do it.

Also, is there another relay that we could use instead of 641 which would give us less steering assistance? How about the one used in RS4? I never drove an RS4 but I would expect that its steering is heavier than the one from S4. Can we use that one in S4 to make it heavier?

Thanks!
Fox

[go_getta]

Thanks eddieman, just did the identical mod...cant wait for the drive home

[dparm]

Thanks for the DIY!

Is there a way of installing the switch without cutting the black wire? I tried to pull out the wire after removing the top part of the socket but I couldn't do it.

Also, is there another relay that we could use instead of 641 which would give us less steering assistance? How about the one used in RS4? I never drove an RS4 but I would expect that its steering is heavier than the one from S4. Can we use that one in S4 to make it heavier?

Thanks!
Fox

The RS4 has different suspension tuning, tires, and wheels, all of which change the steering feel.

[keithwbloom]

I have been wondering about this since I got my S4. I noticed the difference more pointedly when I drove my B5.5 Passat the other day, it's steering input felt so much more dialed in.

It is cool that it has been refreshed recently and came to the top of the posting activity. I would have never thought of the right terms to look/search for, and I loathe asking uneducated questions.

I have bookmarked the thread, and will get started on a switch option right away. I think a modified FUNK button will suffice, my kids liked the FUNK button on my Passat purely for giggle factor. I have also been wondering what I could do with the three button blanks in the center console, I guess this solves for one of them.

:wrench:

[kmarei]

Did this mod on my s4 cabrio
Module is numbered 628 on the cab, I have an on off switch
Don't really like it on corners (too much effort), but much more stable on highway
And to those that say it only affects low speed driving, that's wrong.
Even at highway speeds (70-80) steering is much firmer with the mod
Wish I could have it speed activated :)

[kmarei]

I have been wondering about this since I got my S4. I noticed the difference more pointedly when I drove my B5.5 Passat the other day, it's steering input felt so much more dialed in.

It is cool that it has been refreshed recently and came to the top of the posting activity. I would have never thought of the right terms to look/search for, and I loathe asking uneducated questions.

I have bookmarked the thread, and will get started on a switch option right away. I think a modified FUNK button will suffice, my kids liked the FUNK button on my Passat purely for giggle factor. I have also been wondering what I could do with the three button blanks in the center console, I guess this solves for one of them.

:wrench:

You're welcome to try my car before you do it
In case you don't like it, you don't go cutting wires etc :)
I live in Reston and work in McLean