Cruise control how to, AHU.

jackbombay

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This is not all that bad actually, despite there being little to no information available online. I have an AHU swapped into an old vehicle, fwiw.

First off I VAG-commed a friends Passat and poked around witha test light so I could see what changed in channel 6 (engine measuring blocks) when you hit the brakes, clutch, set button, turned the cruise on, and hit the resume button.

Here are the details on that,
Cruise off: 000 000000
Cruise on: 000 000001

the following are all with the cruise switch on:
Clutch pedal depressed: 100 100001
Brake pedal depressed: 011 010001
Set button while depressed: 000 000101
resume button while depressed: 000 001001

You can use the above information to make sure you have it all set up right before you road test it.

Here is what the switches need to do,


(you need to pull the plug off the ECU to see all th enumbers for the various pins)

Clutch pedal switch: When the pedal is depressed the circut needs to be broken, the wire that needs to be un-grounded when the pedal is depressed is the white with red stripe wire from pin# 17 on the 68 pin connector, all the wires are from the 68 pin plug so I won't repeat that.


Brake pedal switch: 2 wires need to be connected to ground from a switch with 2 circuits, one circuit needs to be complete to ground when the pedal is not depressed (pin #20) and when the pedal is depressed pin #44 needs to become a complete circuit (and the pin #20 circuit needs to be broken at that same time. White with yellow stripe, pin #20 and black with red stripe, pin #44. According to some other info I found online one of those needed to be connected to 12V at the same time the other was grounded, but both hooked to ground worked for me.

I did mess around hooking up both of those wires to power and to ground trying to get it all to work and didn't screw anything up so mess with it however you want, just make sure it all works according to Vag-com as posted above. If you fry your ECU though it's not my fault.

For the cruise buttons themself:
Continous power supplied to pin #66, balck with white stripe, turns/keeps the cruise control on, power removed from pin 66 turns it off.

Your set button when pressed should momentarily send power to pin #35 which is a solid red wire.

Your resume button when pressed should momentarily send power to pin #34 blue wire with green stripe.
.
You'll also need to wire the VSS (Vehicle Speed Signal) to the ecu, that needs to be hooked up to pin #43 blue wire with white stripe.

Hope this helps!
 
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sdturbo

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Thats a project I forgot about... I wired it all up and the cruise never worked. I was thinking im having trouble getting the ecu to like the volvo VSS. I did try to get tricky with the brake pedal and make one ground and one go to 12v. I suppose I should try grounding both.
 
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markward

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82 Vanagon and 2011 JSW
Josh did you enable cruise control on the ECU through the VAG COM software? The VAG COM software should show you if the ECU is seeing the VSS signal and show a speed. Also the brake activation switch is a two way switch. The ECU needs to know the brakes are off and at the sametime when they come on. The ECU actually gets a ground through the brake light bulbs when the brakes are off. I used a brake pedal switch from a 98 new beetle. Had to make a bracket to hold it.
 

jackbombay

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A4 Jetta
sdturbo said:
Thats a project I forgot about... I wired it all up and the cruise never worked. I was thinking im having trouble getting the ecu to like the volvo VSS. I did try to get tricky with the brake pedal and make one ground and one go to 12v. I suppose I should try grounding both.
Did you check the ones and zeros in measuring block 6 of vag-com?

Cruise off: 000 000000
Cruise on: 000 000001

the following are all with the cruise switch on:
Clutch pedal depressed: 100 100001
Brake pedal depressed: 011 010001
Set button while depressed: 000 000101
resume button while depressed: 000 001001

rsxsr said:
The ECU needs to know the brakes are off and at the sametime when they come on.
I fidled around with making that happen foro a while only to find that both of the "brake wires" simply needed to be grounded when the brake pedal is depressed, I used alittle sub mini lever switch from radio shack that ground both when it clicks.
 

clyde

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1998 Jetta, 1959 DeSoto with leopard-skin seat covers
What is the "old vehicle" that has your TDI?

Where did you get the speed signal for the cruise system? Did you use the TDI transmission and take the VSS signal from the sender on the trans?

If you didn't use the TDI trans & VSS signal, what produces the speed signal?
 

jackbombay

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clyde said:
What is the "old vehicle" that has your TDI?
Vanagon.

clyde said:
Where did you get the speed signal for the cruise system?
I have a VSS generator bought from Fast Froward (no longer in buisness) that plugs into the back of the speedo.

You can also zip tie 2 magnets to one of your drive shafts and mount a pick-up close by and use that as your VSS, amny aftermarket cruise controlls have this option, you might try JC Whitney to see if they sell the pick-up seperately.
 

compu_85

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... None :S
You might be able to get the speed pickip from a Mk2 Golf / Jetta with cruise control... they have a small one screwed into the back of the speedo. I can look up the part number if you want, it is a VDO part.

-Jason
 

G60ING

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Alexandria, VA
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No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
the 1990 corrado and passat clusters pick up the speed in the cluster too and after 1991 they ditched this infavor of elminating the speedo cable.
 

clyde

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confluence, Snake/Clearwater
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1998 Jetta, 1959 DeSoto with leopard-skin seat covers
Don't know much about cruise sensors, but do know that there were at least two sensors used in the A2 VW Golf/Jetta vehicles. Both of these fit in the speedometer head. The Hall-effect sensor clips to a piece of the flexible printed circuit on the back of the instrument cluster.

A Hall-effect sensor provides the speed signal in my two cars—a plain-Jane 85 diesel Jetta and a 1986 gas Golf. Both cruise systems are the same, with switches for brake and clutch pedals, On-Off switch in the turn signal control handle, control unit, vacuum pump, hose, and diaphragm to operate the throttle.

Because cruise in the TDI is operated electrically, the TDI will use only the On-Off and pedal switches and a speed signal from the sensor in the speed head—I hope.

The bottom-line question is: Does the Hall-effect sensor from the A2 Golf/Jetta provide an appropriate signal so the TDI ECU can operate the cruise function?
 

AndyBees

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Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Darn! Based on the small amount of reading I have been doing here, I am in for a lot of work installing a TDI in my '84 Vanagon.

I have the TDI engine, cluster, ecu, complete wiring harness, key and key switch. However, it seems there will be a lot to do to make all the systems work. Oh, and I do have an '82 Vanagon Diesel tranny.

This is a project I would like to get under way and complete in '08!
 

jackbombay

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A4 Jetta
AndyBees said:
I have the TDI engine,
AHU or ALH?

You'll have to budget for getting the trans regeared. Mine has a .77 4th and a 1:1 3rd and I have the biggest tire I could fit and still have clearance to run chains if needed. 195 75 16. they are 27.5" in diameter, and dropped the RPM ~%10 compared to the stock tire size, with the .77 4th it is a really nice combo. Stock tires and the .77 had the engine spinning a little faster than ideal.
 

AndyBees

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Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
My engine is an ALH.

What are the RPMs at 65 mph on your set-up?

I would like to find the combo to be cranking about 2500 rpms at 65 mph. I hope that's possible.
 

jackbombay

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AndyBees said:
My engine is an ALH.

What are the RPMs at 65 mph on your set-up?

I would like to find the combo to be cranking about 2500 rpms at 65 mph. I hope that's possible.
I'm spinning 2900 at 65, its pretty good there, not sure I'd want it geared higher, ready to travel it weighs ~4,500 pounds and the aero is, well...


I have a .77 4th, but you can get a .70 4th, I have a higher 3rd as well, 1:1, and the jump from 3rd to 4th is already on the edge of acceptable IMO. Not sure if you can get an even taller 3rd and a taller 2nd. A 4 speed and a fairly low final drive is not the best to work with.
 

clyde

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1998 Jetta, 1959 DeSoto with leopard-skin seat covers
On this conversion, the speed signal from the Hall sensor in the speedo head goes to connector U2 pin 2, then to connector W pin 1. In the A2 cruise system this speed signal would go from W-1 to the cruise brain. BUT, as the A2 cruise brain won't be used, I think the wire from W-1 should be connected to the blue-white wire that went to the VSS in the 1997 car. That will take the speed signal to the TDI ECU, which runs the cruise system.

Does that seem right?

I'll appreciate your comments.
 

Lone Ranger

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Winnipeg MB
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TDI Ranger
Cruise

Well this topic is very interesting to me, I so want cruise in my Ranger(it has a 2002 TDI for a power plant) and you can read all about it in the converstion section TD Ranger or TDR.
Anyway if someone has the same info for the AHU that jackbombay has posted but for the ALH? I believe its an ALH in my ranger?
Well I have made several attempts to get it working and to no avail. Which is just bizarre cause I have the motor in a ranger transplanted all the electronics and that all works but I can`t get the cruise to work!!
I'm sure it uses a signal from the ABS control unit(which i am not using)seeing as it has wheel sensors and my local VW dealer tells me if there is wheel slippage the cruise is automatically disabled. Any info any of you have on this would be greatly appreciated, I just need a point in the right direction and I know I can make it happen
 

jackbombay

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You could try the yahoo Westfalia/vanagon TDI conversion group, they are quite a knowledgeable bunch of guys.

Do you have all the ones and zeros in the correct places (looking in vag-com) letting you know that the cruise is on, the brake off, etc...?

And you have a good VSS source for the ECU as well?
 

Lone Ranger

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Vss

Well thats just it, I don`t have a vag-com so its trial and error so I have no idea about the 1's and 0's. Also would it be the same from ALH to AHU? I have the VSS hooked the the tail shaft of the ford tranny. I have a reading on the speedo which is the original dash cluster of the jetta albeit its a little off but still it should work. Does the VSS not feed into the ECU? I thought the signal would be carried by the CAN-bus between the dash cluster and ECU, or does it need to go direct to the ECU from the VSS aswell as to the speedo!
 

jackbombay

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With my AHU install the VSS goes straight to the ECU as I don't need the dash cluster for the immobilizer, but if your cluster is hooked up to the ECU it seem like that should be fine.

If the VSS does not match reality thats fine, the ECU just needs to see something.

Below is a link to the "vag-com list" here, check it and see if there is someone in your area that can help you out, without vag-com to confirm that the various switches are functioning as they are supposed to you could be chasing a problem that does not exist.

http://anglo-hexon.net:88/beowulf9/tdi/vagcom/

If you need I can get you the "one and zeros" from my ALH, but my buddy has it out of town for the next week so I can't do it till then.
 

jimbote

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Andybees, my friend has a 82 westy diesel that he converted to aaz....he sent the tranny off and had an aircooled ring and pinion installed....not sure on the ratios but it does much better on the highway now.....
 

Lone Ranger

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Well if its not too much trouble to get the ALH numbers with the vag, then I suppose they won`t hurt, but I'm sure my problem lies with the ABS control module.
Someone Should do me a huge favor and disconnect all their wheel sensors on a 1999-2002 jetta TDI and tell me if their cruise still works with them not connected:D If it dosen`t then I'll have to figure out away to fake an ABS unit or just find the wire to the ECU thats needs signal from the ABS unit in order for the cruise to activate.
 

e*clipse

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Toyota TDI swap
Thanks for the info JB! :cool:

Do you have any info about what signal the speedometer or ECU is expecting from the vss? I'm assuming a 0-12V pulse, but how many pulses per revolution?

My truck project is going to use a new(er) speedo from a 1994 'Yota and a pulse generator that puts out a 0-12V pulse 4 times per driveshaft revolution.

There is also a pulse generator for the rear ABS that puts out a pulse every time a rear diff. tooth passes.

Either should work; I just need to meet the ECU's and speedometer's requirements.

I think I've seen posts saying the 1Z motor's speed sensor puts out 4 12V pulses per revolution (PLEEEZE correct me if I'm wrong)

SD, what are you doing about the tach and speedo signals?
 

jackbombay

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e*clipse said:
Thanks for the info JB! :cool:

Do you have any info about what signal the speedometer or ECU is expecting from the vss? I'm assuming a 0-12V pulse, but how many pulses per revolution?
I've read that attaching 2 magnets to an axle on a vanagon with a pick-up close enough to "read" the pulses works.

FWIW, I have a VSS generator from "Fast forward" (no longer in business) plugged into the back of my speedo.
 

tongboy

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Lone Ranger said:
Well if its not too much trouble to get the ALH numbers with the vag, then I suppose they won`t hurt, but I'm sure my problem lies with the ABS control module.
Someone Should do me a huge favor and disconnect all their wheel sensors on a 1999-2002 jetta TDI and tell me if their cruise still works with them not connected:D If it dosen`t then I'll have to figure out away to fake an ABS unit or just find the wire to the ECU thats needs signal from the ABS unit in order for the cruise to activate.
No abs computer is needed at all to have cruise function, the keys are vss signal to the edu and making sure the brake and clutch sensors all report the correct values to the ecu, done of them are regularly high, some regularly low, the wiring diagram from the donor should denote which are which, the cruise stalk inputs are simple after that
 

markward

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You need to verify that the ECU has cruise activated. Can be activated using the VAG COM. I would have never got mine working without the VAG COM to use.
 

Lone Ranger

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no abs?

Hmm, so the abs computer dosen`t have to be present inorder for cruise to function you say? But it can deactivate it when there is wheel slip detected, correct?
That said, I did not have either the brake or clutch switches hooked up. Are they not just there just to deactivate it when pressed? Its just a signal sent when depressed, or is there more to it than just a simple on off?

and by the way, thanks for all your input jack and tong
 

Lone Ranger

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Also tongboy, my wiring diagram shows the VSS feeding directly to the dash cluster? Are you saying it needs to go to the ECU aswell? Would the VSS info not be shared via the can-bus to the ecu from the dash cluster, if not, how would one get the VSS info to the ecu? ie. what wires from the ecu. cause I have nothing that shows me where there could be an input to the ecu for the VSS
 

jackbombay

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Lone Ranger said:
Hmm, so the abs computer dosen`t have to be present inorder for cruise to function you say? But it can deactivate it when there is wheel slip detected, correct?
If the ESP (quite different from ABS, but ABS is part of ESP) system detects wheel slip from throttle application the cruise will get turned off, but the ABS is only working, or ready to work, when you push the brake at which point the cruise is already off.

Lone Ranger said:
That said, I did not have either the brake or clutch switches hooked up. Are they not just there just to deactivate it when pressed? Its just a signal sent when depressed, or is there more to it than just a simple on off?
The clutch switch just needs a simple switch where the circuit is broken when the pedal is depressed (or the circuit may get completed when the pedal is depressed, the first post of this thread has the details).

The brake pedal needs a switch with one normally closed circuit and one normally open, both of those circuits go to ground, when the one circuit closes from the brake pedal getting pushed the other must open at the same time, I found a single switch from radio shack that works great.

Thats how it was on my AHU at least.

and by the way, thanks for all your input jack and tong[/quote]
 

markward

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I am using the OE brake pedal switch from a 98 New Beetle on my vanagon. From memory. The description of the switch operation is correct, but I found the ECU needed to see the brake light bulbs to keep a code from showing up. The ECU gets a ground through the actual brake bulb filaments when off. When the pedal is depressed and the bulbs light, the ECU sees this change of state.

I am aware of this, because on the vanagon, I was using the original hydraulic pressure switches to activate the brake lights and the pedal switch to "talk" to the ecu. Not until I moved the brake lights onto the two way pedal switch did the code go away. I then worked on getting the cruise to work. My ECU was not coded for cruise control out of the box. It took two tries for the ECU to accept the cruise control.
 
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