*DIY* - Making your Cruise Control work after 5-speed Swap (DBW)

[walky_talky20]

>> PDF Version with Photos - Click Here <<

So there are a few of us that have 5-speed swapped our rides. And as awesome as that is (and it's pretty fricking awesome, mind you), there still are a few things left as loose ends. Namely the lack of working cruise control. While there are those of us who do not use, do not need, or do not care about the cruise, these are luxury cars and that is one of the many amenities. Also I have a seriously long drive to work and this was getting pretty annoying.

Note: There is also the issue of no reverse lights. While I may cover that at some point in the future, this DIY is aimed squarely at the Cruise Control Situation, or CCS, as I like to call it.

Note 2: This entire DIY applies to DBW (Drive-By-Wire) cars only (2000+). So ATW and AWM for the 1.8T's and ATQ for the V6 guys.

Explanation of the problem. The reason that the cruise control does not activate is because there is no clutch switch input. Once the ECU is recoded to manual, it expects to see this input as safety for using cruise control with a manual trans. Because our cars have an automatic harness, there is no provision for plugging in the clutch switch. I figured it was just a matter of finding the wire and connecting into it, but in fact the wire does not exist at all in the automatic harness. It is simply not there, all the way back to the ECU. So we must add it.

I have separated this into 2 parts or "phases" if you will. Phase 1 is adding the input wire at the ECU. Phase 2 will be adding the clutch switch and wiring it up at the pedals. The phases are really meaningless. Are you really going to *just* do phase 1? I think not. However it does serve to make my DIY seem more planned out, and somewhat less "thrown together".

Let's begin.

Phase 1:
*First thing when doing electrical work is to disconnect the battery. Just disconnect the negative terminal at the battery and swing it aside.

Pop off the plastic covering the battery tray and brake booster. This will reveal the ECU plenum chamber (ie: the plastic box).


You will need to remove the five 8mm hex head screws that hold on the top cover. The back 2 are little tricky to get at without removing the wiper arms and rain tray, but it can be done. I have elected to never put those ones back in. Now the cover is off and you can see your ECU. Yay.


We are interested in the largest ECU connector, nearest the driver's side fender. Pull out the slide clip thingy to unplug it.


Now we have to disassemble the connector housing. You will notice 2 purple clips on either side. Using a small pointy object or a safety pin, slide those guys out.


With them fully removed (don't lose them!), the innards of the connector will be removable. I did not take a photo of the rear connector cover piece. It is pretty simple, you just cut the zip tie and pop it off. With the connector disassembled it will look like this.


The pin we are interested in is number 39, the clutch switch input to the ECU. There are numbers on the outer connector housing to help you with the numbering, In this photo we are looking at pin 43 (at the bottom, green wire). Counting up 5 spots we come to pin 39, identified by the RED arrow. Note there is no wire here, which is why we must dig down this far. To remove the blank pin you use your pick or safety pin again and push up on the metal clip, identified by the BLUE arrow. Once that is pushed in, you slide the pin out in the direction of the ORANGE arrow.


Now we are in possession of a seriously tiny pin with no wire attached. Ta-da.


Grab a nice piece of wire. The size is important as it has to fit in the pin. I think the wire shown here is about 18 AWG, maybe smaller. The length will need to be 3 feet or so. Strip one end a get it to fit into the pin nicely. Like-a-so:


Then a quick solder job. You must be careful not to glob the solder on the sides of the pin housing, or any further forward than the wire goes, else it will not slide back into the connector housing properly. Ask me how I know this...


Not too bad for using hugely oversized tools for the job.


Now the pin slides back into the inner connector housing.


Reinstall the purple clips and then clip on the rear connector cover, replacing the zip-tie.


Plug the ECU back in and feed the length of wire down into the abyss.


This concludes Phase 1. You can now clip your ECU back down and reinstall all the plastic covers. Leave the battery disconnected for now.

Phase 2:
Here are the final pieces that we need to get this done. We need 1 small butt connector and 1 small scotch lock. For my clutch switch, I harvested a vacuum vent switch (brake switch for cruise control) from a 1993 Audi 100 S automatic. Behold.


Drop the knee bolster in joe-audi (wait, this isn't your Audi? I hope you're getting paid for this crap.) and find the wire that you fed down into the car. Mine is red.


In this lousy picture I am showing the red wire is crimped onto one of the switch wires (black/green) using a pink butt connector. It is also showing the blue scotch lock which is connecting to the other switch wire (black/yellow) and tapping it into the brake light switch wire (black/blue).


Then the new clutch switch gets threaded into it's respective hole and adjusted "just right". So the switch is just fully depressed with the pedal at rest. Once it's plugged in, we are all done here. Make sure to zippy-strap your wires out of harms way before buttoning everything up.


Now you can reconnect your battery. Make sure to reset your dash clock and all your radio presets, cause that's important.
This concludes Phase 2. You may now try out your cruise control.

Results:

I now have functioning cruise control. Real, pure, OEM, not-from-concentrate Cruise Control. And it fricking WORKS. I should have done this months ago.

Also, I have noticed that this fixes MORE than just the cruise. Yes, you heard that right. With back to back testing I have noticed that having a clutch switch greatly helps the "throttle hang" issue when shifting at full throttle/high rpm. Whenever I would shift for example 3>4 at full throttle around 3000 rpm or more, the revs would actually go UP during the shift, no matter how careful I was with my timing of the pedals. I thought it was just my stupid-heavy OEM dual-mass flywheel. Such is not the case. This throttle hang and rev-up issue is 100% better now after the clutch switch install. I am excited to see if it fixes anything else. I do have another issue where my car likes to run like complete crap the moment I drop the clutch. Especially with the A/C on. Almost like trying to start off in second gear or something. It just won't get off the line unless I "launch" it. We'll see how that goes.

[revolution337]

awesome write up walky This will definitely be a help for those who 5sp swapped.

edit: question though, how do you pass PA inspection with no reverse lights?

[walky_talky20]

Indeed, I think it will be quite helpful to a very, very select group of people probably numbering less than 5. And it will no help at all for everyone else.

And that is a great question. Actually, I did my 5 speed swap a few months ago and my inspection runs out ah....next week. So the reverse light DIY will probably be quite forthcoming! But my dad has his own shop, so you could say "I know a guy".

[biketsai]

I havent read through it yet, but I just wanted to say THANK YOU!!

Edit: Just read through it, so just how hard was it to do? I know the clutch switch will be cake.
Im even more excited to hear about the throttle hang. Likewise, I thought it was my LWFW!!

Chris

[Papa_Dios]

Great job!! I was having my buddy look through the bentley too figure out how to do this (as I don't mess with electricity lol). I'm going to try this ASAP. Do you have a part # for that brake switch?

[walky_talky20]

It wasn't hard to do at all. The trickiest part was really soldering the wire to the blank pin, but even that is plenty easy if you have a normal sized soldering iron.

This was the switch I used:
http://www.ecstuning.com/Search/811907343b/ES251756/

I got it used, they are very plentiful and nobody needs them. Every Audi from 1980 or so with cruise control has one. I figured most of you guys got them included with your pedal cluster, but mine was gone. In any case, if anybody needs one I can probably get one to you with the connector for like $10. You can also just use a second 4-pin brake light switch, like this one:
http://www.ecstuning.com/Search/4a0945515a/ES2707/

They thread into the same type of holes. The larger pins are "normally open" and are for the actual brake lights. The smaller pins are "normally closed" and are for the cruise control. But you'd have to find a harness "pigtail" to use with it as the pins are round, not flat.

I really put this off because I thought I would need special tools to work with the ECU pins. After looking up a Jetta coil pack harness replacement DIY (which replaces the wires all the way to the ECU) it became clear that this was a lot easier than I had thought. My original plan was just to "harvest" one of the pins that already had a wire attached, that was originally for the Auto Trans stuff. Come to find out the way that ME7 talks from the ECU to the TCU is completely different. So that method would work for a 2000 (there are like 7 different wires that run directly from ECU to TCU), but for a 2001 all those wires were gone. I believe it uses CAN bus or some-such. So I just had to solder on a wire.

I was hoping this would be useful for a couple people. But I basically wrote it up for you 2 guys.

So, do you guys have reverse lights yet? That's my next project I think. And an oil change, and front brakes, and....

[revolution337]

I have a spare clutch switch (the same part # as the one walky used) that I'd be willing to send to anyone who is in need of one for this mod. Let me know

[Papa_Dios]

Gotcha. I'm going to check my pedal cluster and report back. I read on doing the reverse lights. It involves swapping over some wiring from the auto tranny correct?

[biketsai]

I have a spare clutch switch (the same part # as the one walky used) that I'd be willing to send to anyone who is in need of one for this mod. Let me know

PM'd!

[biketsai]

Gotcha. I'm going to check my pedal cluster and report back. I read on doing the reverse lights. It involves swapping over some wiring from the auto tranny correct?

Something like that, I remember I wasn't too interested after reading on how to do it.

Moved to DIY's

[walky_talky20]

I think the reverse lights will be even easier. It is just 2 wires to the reverse switch. Just have to find a suitable donor for the connector. I'm hoping the 93 100 S will fess up a connector for that as well!

[biketsai]

Just got my clutch switch, gonna tackle this tomorrow!

[revolution337]

Just got my clutch switch, gonna tackle this tomorrow!

[biketsai]

Just finally got around to finishing this. The longest part was trying to solder the damn thing! I suck at soldering, and it didnt help that I had some huge soldering iron. I ended up not even soldering it, and just crimping it on the end (there is a little tab on both sides to do so).
Glad I wont have to make monthly 3-hr drives without CC anymore!

Thanks again for this thread.

[walky_talky20]

You are very welcome. Glad you finally pulled the trigger. The first time the cruise kicked in...magical, right?

Did it also fix the throttle hang on shifts for you? For me, that was almost as annoying as the lack of cruise.

[KraemerSXED]

This thread and your reverse light thread will be very helpful for me coming up soon here. With some slight differences that I hope won't be a problem.

[3 bar]

Working on a 5 speed swap on a passat I bought as a daily. Thanks for the info!

[walky_talky20]

No problem sir. 3 pedals FTW.

[VAGguy]

I wanted to add my Observations doing this to my 2004 manual swapped Passat 1.8t wagon. I did the swap in CT and drove the next day. I had wired the reverse lights, but rarely used cruise so I left this for when I got back to MD 325 miles later. I barely got 30mpg the whole trip back. Less than going up to CT with a full car and auto.

The whole trip back, throttle hang and lower power than I expected. Also, the acceleration was choppy at times. Even in the peak of the expected power band. Wiring in the switch took care of the cruise, throttle hang, acceleration and mileage. It's like a totally different car after the switch install.

[wafi ahmed]

Without wiring clutch switch I’d have rev hang issue no? Cuz I’m having rev hang rn and it’s taking long time to shift


Sent from my iPhone using Audizine Forum

[VAGguy]

Yes. that is correct.