Retrofitting cruise control: questions

[Stonejag 10]

Hi all,

 

Just taken delivery of a huge pile of lucky-dip cruise control parts from an auction on German eBay. Has anybody got this fitted to their RHD Corrado at the moment? If not it looks like I'll be the guinea pig documenting as he goes along...:lol:

 

Pretty sure I've got all the bits I'll need, it's just:

Vacuum pump + harness

Complete pedal box with vacuum throttle actuator, bracket and combo brake switch

All the vacuum hoses

Indicator + cruise stalk for late interior

ECU and wiring harness

 

All the parts are from a B3 Passat VR6 auto. The ECU is part number 1H0 907 305 but the Corrado equivalent is 535 907 305 so I'm hoping it's the same.

 

My main question is in how the vacuum actuator (VW call it a 'throttle control element') attaches to the gas pedal. It's very straightforward on LHD cars, which is what's shown in ETKA / Vagcat and on my new pedal box - the throttle cable attaches directly to the pedal, and the actuator attaches just behind the pivot so that when vacuum sucks the arm into the actuator body the pedal is depressed. Unfortunately the pedal box is totally different for RHD cars as we have the weird horizontal bar attached to the gas pedal which then moves an arm to the left of the clutch pedal which pulls the throttle cable. It's really unclear to me from this diagram:

 

 

It's allegedly the same bracket and actuator for both types, it's just not very obvious at first glance :) Hopefully someone has done this before and can snap me a quick pic so I can visualise it better. After that it's supposed to be fairly smooth sailing 8)

 

Thanks in advance,

 

Stone

[Riley 0]

Isn't the original throttle cable retained? And the vac actuator sits on the throttle body connected to a second ball joint? The vac then has tubing running to the push/pull rods which are attached to the pedal?

 

Sorry if I've misunderstood. I've actually got some cruise control bits knocking about somewhere as I looked into fitting it some years ago myself.

[Stonejag 10]

You're right; I forgot to mention there are two completely contradictory diagrams in ETKA! This one is much closer to the bits I have:

 

 

The vacuum actuator attaches to the gas pedal somehow - looks like the same place the balance weight bolts onto the pedal but it's so hard to see what's going on behind the fusebox that I don't really know what's going on. Need to clean the stalk up and get the cracked bits swapped over first, then I'll ;ay it all out on the floor and have a play with a 12V supply :)

 

Stone

[Riley 0]

Ahh yep. That picture rings a bell! Just remind me of the difference, isn't it that the bottom setup showing auto/ cars? Just trying to jog my own memory a little more. I think (IIRC) I was going with the top picture when I was looking into it, and was going to modify the pedal to accept the push/pull jobby's.

 

If I can get my old pc working with etka installed I'll have a look and try and remember what I was planning...See if it can help.

[OllieVR6 0]

Ooh interesting. I'll be watching this with interest. Definitely a 'toy' I'd like (along with climate control and electric seats haha).

[VR6 Lee 0]

I so need cruise control on the corrado and a 6th gear...lol

[Stonejag 10]

Started getting it all laid out so I know what's what. Here's a few pics!

 

Everything out of the box:

 

Vacuum actuator on top of the pedal - the light grey arm pulls on the very top of the pedal, above the clip where the balance weight goes. The actuator arm clips onto a ball-shaped protrusion at the top of the pedal - not sure if my pedal has this or I'll need to add it. I could swap the pedal over, but it's a load of work just to find out if this one will fit, so it'll probably be easier to manufacture something to fit into the pedal if I need to...

 

The (blue) brake ventilation valve goes just behind the brake light switch on the same bracket. It has a vacuum line T-ed off the feed to the actuator so the vacuum is released when you press the pedal, and an electrical switch to tell the ECU to shut down. There's an identical switch on the clutch pedal if you have a manual, in which case the vacuum feed has a double-T so that either brake or clutch can let the vacuum escape. The loom's different as well, as this auto one hasn't got an extra plug for the clutch switch.

 

The ECU, with its bracket. Not sure but I think the cruise control module / immobiliser may be intended to go on this bracket too? Mine have all been messed about with and are dangling free, so it gives a convenient place to put them all anyway!

 

Vacuum pump with its bracket. Not sure where I'm going to put this yet - probably inside the engine bay rather than its stock (stupid) location behind the passenger-side wheel arch liner. Yes, really! One vacuum feed and a three-pin connection to the ECU.

 

The stalk - had to take this apart earlier to repair the sleeving over the cable as it had torn. Useful tips: the connector is in two parts which unclip so you can get at the pins (don't pull them out of the connector with pliers after releasing the locking tab, it won't work properly!). Release the front cover by putting the indicator switch in the middle position and undoing the single Torx screw on the left and the three plastic clips, then you can wrestle with the lever until it comes free. When reassembling make sure you get everything back as it was - the lever contacts a low-friction plastic piece, if you have it touching the spring you've got it in the wrong order. To get the cover back on, ensure the sprung white plastic piece is in its groove first, seat the left-hand side by wiggling the lever slightly, then push the sprung white bit to the outside to get the right side on. Push the clips home and put the Torx screw back. Took a good twenty minutes to work that out!

 

Some mystery connectors on the part of the loom near the fusebox. Blue/white is speed signal, then I assume brown is ground. The other two are black with red stripe (green plug) and black with yellow stripe (white plug) - anyone know where these plug in? Is the back of the fusebox colour-coded? Not taken it off yet...

 

More mystery connectors at the vacuum pump end of the loom - a 4-pin red one and a pair of two-pin black ones, one large and one small. I think the red one may be a test connector but not sure...

 

Think I've answered my own question with the accelerator linkage - even with the undertrays off I couldn't quite see the top of the pedal so I must have to take off the fusebox to get at the hole the actuator mounts to. The mounting bracket is the same part number as a Corrado one (357 721 819) so it should bolt straight on, just one bolt and a nyloc nut.

 

I've lost the link now but I did find a German website with instructions for testing everything outside the car, so when I've found it again I'll have a play with that :)

 

Stone

Edited October 25, 2012 by Stonejag

[Goldie 2]

Watching this with interest.. I don't recall anyone fitting cruise control to a Corrado (without using a modern engine and the trimmings to go with)..

 

Fair play to you...

[Stonejag 10]

Well, the pedal box is totally different and there's nowhere obvious to fit the throttle control element...the top of the RHD pedal is welded directly to the cross-bar that rotates and pulls on the throttle cable to the left of where the clutch pedal goes. I may be able to fit it upside-down on the far left (so it pulls on the cable directly) but without a test-fit I can't work out whether it would intrude into the footwell. Perhaps this is why the second system was developed, with an extra cable pulling on the throttle body?

 

Still very interested in seeing pics of any RHD Corrados with cruise control :)

 

Stone

[Stonejag 10]

Progress!

 

I haven't looked at a way to mount the actuator yet, but after a LOT of trawling obscure German websites I finally found a circuit diagram that matches the system I have :D

 

 

This diagram is for the B3 Passat (35i) but should hold true for anyone using the same cruise module (Jetta, early Mk3 Golf and Golf Cabrio etc etc) with part number 1H0 907 305. So, time to answer some of my own questions!

 

The four loose plugs at the fusebox/ECU end of the loom are:

Brown plug, brown wire: Ground

Blue plug, blue/white wire: Speed signal (should be a matching loose connector in the loom behind the fusebox, not looked yet)

White plug, black/yellow wire: Switched live (fused supply to ECU via stalk)

Green plug, black/red wire: Fuse 20, permanent live, fed to the ECU through the pedal switch; in series through both if it's a manual. The Bentley says it's fusebox terminal E/3 for the Corrado, not W/4 as for the Passat. Should clip onto the green plug for E/4 which powers one side of the brake light switch.

 

Still no idea what the red 4-pin connector or the two bonus engine-bay connectors are, I'll buzz them out later once I've finished confirming my harness matches the diagram - it's looking good so far though. Once I'm nailed those down I'll know enough to get it electrically connected, then I can worry about the pedal actuator. I have some ideas on that front...slightly complicated by it being my daily driver though, so I have to be able to do it with the pedal box fitted! More as and when.

 

Stone

[Stonejag 10]

[...time passes...]

Still no idea what the red 4-pin connector or the two bonus engine-bay connectors are, I'll buzz them out later once I've finished confirming my harness matches the diagram - it's looking good so far though.

There was a simple solution, turned out the last three plugs were only attached to each other and not interconnected with the cruise system at all, so they must just have been sharing a grommet into the Passat's engine bay with the cruise loom. A quick snip later and my loom's looking much simpler, with all the plugs now identified! :thumbleft:

 

The rest of the loom was identical to the above diagram, but with two of the pins swapped over on the stalk's connector. All looks factory so I'll test it out before modifying it - probably just an early-stalk/late-stalk change.

 

My gf's out this weekend so I'll have a good poke around the scrapyard tomorrow and see if I can unearth any 8mm ball studs like this one:

(normal VW gas struts for holding boot lids open are 10mm, annoyingly) Then I can start mocking up something to add to my pedal cluster...

 

Stone

Edited November 2, 2012 by Stonejag

[RW1 0]

[...time passes...]

 

There was a simple solution, turned out the last three plugs were only attached to each other and not interconnected with the cruise system at all, so they must just have been sharing a grommet into the Passat's engine bay with the cruise loom. A quick snip later and my loom's looking much simpler, with all the plugs now identified! :thumbleft:

 

The rest of the loom was identical to the above diagram, but with two of the pins swapped over on the stalk's connector. All looks factory so I'll test it out before modifying it - probably just an early-stalk/late-stalk change.

 

The red to two black connectors is part of a loom for use with the LHD Factory fit alarm system. Just happens to use the Cruise loom to pass through the firewall bulkhead. Specific to the Passat loom, not the Corrado equivalent Cruise loom.

 

I don't remember the UK Corrado having a Cruise Control fitted at the factory. The parts are for LHD only. That means you need to be aware of the Teves02 brake system coupling through the firewall. Not sure they are the same as the UK Teves04. And as you've discovered, the accelerator is LHD. The RHD is the way it is to avoid a foul fit with the fuse box which doesn't exist on the left side in LHD build.

 

Wiring diagram is OK.

 

The only RHD Corrado UK I know that was fitted by an owner was a aftermarket one from Ultimate Design in Kettering (http://www.ultimatedesign.co.uk/Cruise1.html#CRUISE). It still used the Corrado Cruise Control Stalk for its switching. Featured in the Sprinter August 1999. No real technical how to.

 

.

Edited November 3, 2012 by RW1

[fendervg 33]

I was planning to go with a different kit - an aftermarket one, but haven't got around to fitting it yet - all I have is the stalk in place.

http://the-corrado.net/showthread.php?46616-Retrofit-GRA-Cruise-Control&highlight=cruise+control

[Stonejag 10]

The red to two black connectors is part of a loom for use with the LHD Factory fit alarm system. Just happens to use the Cruise loom to pass through the firewall bulkhead. Specific to the Passat loom, not the Corrado equivalent Cruise loom.:

Thank you, always nice to have confirmation so there's no niggling doubt :)

 

I don't remember the UK Corrado having a Cruise Control fitted at the factory. The parts are for LHD only. That means you need to be aware of the Teves02 brake system coupling through the firewall. Not sure they are the same as the UK Teves04. And as you've discovered' date=' the accelerator is LHD. The RHD is the way it is to avoid a foul fit with the fuse box which doesn't exist on the left side in LHD build.[/quote']

I think it was fitted by dealerships on request, since they could order all the parts. I've seen a RHD pedal cluster online (possibly Golf Mk3?) where it's the same as the Corrado one but the throttle pedal arm continues upwards where it's welded to the crossbar rather than being cut off flush, so there may have been an alternative...(then again didn't they have the fusebox fitted in the side of the dash?)

 

I'll see what the parts catalogues can reveal but I'll probably end up tapping a hole into the arm that pulls the throttle cable down (on the far left), putting a threaded ball stud into it and fitting the actuator upside down (arm uppermost) with a new bracket so it pulls more directly on the cable. Tons of room in my car but then I have the lightweight clutch pedal! :lol:

 

The control units are notorious for developing cracked solder joints and having their relay fail, so I'll be reworking that before final fit. Also my stalk has a very touchy Set button - electrically quite poor, so I may find a new one. There doesn't seem to be any way to get into the stalk part so I don't want to scar the plastic prying at it!

 

Stone

Edited November 3, 2012 by Stonejag

[Stonejag 10]

Got around to having a bit more of a play with this today. I've now checked out all the wiring. I resurrected a small lead-acid battery that I had lying around in the house (it was so discharged it only read 1V! Needed quite a lot of high-voltage charging to get it desulphated and accepting charge again...) and was feeling brave so ran the vacuum pump off it to see what would happen. Success :D Took a bit of working out but there's another failsafe feature built into the pump - when the internal valve has power applied to it the vacuum system is sealed, but with no power any vacuum the pump creates instantly escapes through the vent. I'm guessing this is to make triply sure that a system failure can't leave the pedal stuck down due to vacuum still being in the system; the whole system is already vented through the brake pedal switch if you touch the brakes so it's a touch of overkill!

 

With the pump running (12V across pins 2 and 3) there's a small stir of movement on the actuator arm but it has no power behind it. With the vent valve powered, however (pump pins 1 and 3), it's so powerful I can't resist it by hand without endangering the plastic linkage! It's easily powerful enough to pull directly on the throttle cable so when I'm a bit further along I'll start on a bracket to hold it in the right place in the footwell. Alignment doesn't seem to be that crucial due to how the plastic linkage is attached to the actuator so it should be pretty easy, I just need to keep enough clear space to allow the dash undertrays to be refitted.

 

Got hold of a test procedure for the model of ECU I have so I'll be running that tomorrow and then hopefully there aren't many obstacles to getting it all installed :D

 

Stone

[dannyboy 0]

Haha,I had one of these units in my old raddo. Was a bit temperamental at times,think vacuum pump was on the way out. Never seen one in rhd one though.thought because the accelerator was on right tight against the bulkhead there was a different pedal box. You could adapt it but there's very little room.

 

The valves in the clutch and brake pedal release the vacuum disengage the cruise control. Feels freeky the first few times you use it when the accel pedal starts doing its own thing

[Stonejag 10]

Never seen one in rhd one though.thought because the accelerator was on right tight against the bulkhead there was a different pedal box. You could adapt it but there's very little room.

You're right, it's quite tight behind the fusebox! Mine's an auto so there's bags of room where the clutch normally lives, I'm going to fit the actuator upside down in there and have it pulling on the linkage where the throttle cable is attached to the pedal box on the left hand side.

 

There are several safety features but the main one is that brake switch releases the vacuum out of the actuator near-instantly when pressed. The design means the actuator can only pull the pedal down (but doesn't stop you from manually pushing the pedal harder) - it relies on the return spring to pull it back up. The electrical contacts in the brake switch also interrupt power to the cruise ECU when activated so there's a second layer of security there. Also, the vent on the vacuum pump is normally open and requires current from the ECU to keep it closed, so if power fails then the vent will open and the vacuum will escape through the pump. Also (!) the power to the switch is provided from the auto transmission's ECU which prevents the system activating when you're in reverse...so overall it's pretty safe. On a manual that bit isn't there - the clutch switch and brake switch get their power from a regular switched live, but they're in serial so only one needs to be pressed to cut the system off. Given that it's quite complicated, it's pretty well thought out.

 

From having a play with it yesterday it's extremely tolerant to being misaligned (hard to describe though!) so it should be pretty easy to get something working. There's a good couple of inches of adjustment in the linkage so I just have to get it set so the cable isn't being pulled when the cruise actuator's fully extended but fully depressing the gas pedal doesn't make the arm hit the bottom of the actuator. I'll take some pics later but I'm pretty confident!

 

The vacuum pump seems pretty robust - I'm planning to put it in the engine bay though rather than the stock location behind the nearside wheel-arch liner, because that's a really stupid place to put it! It's pretty noisy but it won't make much difference next to a VR6... Apparently they usually fail because the ECU is made really cheaply but I plan to replace a bunch of the weak parts before installing it so it should work out alright.

 

Stone

Edited December 7, 2012 by Stonejag

[Stonejag 10]

Well, I think I've struck the jackpot:

(from [this page])

 

This diagram shows both two types of pedal assembly for a Passat - the bottom one looks pretty much identical to the pedal box that came with my cruise bits, and the top one looks suspiciously like it might be the same as the RHD Corrado part...

 

[edited:

 

I'm pretty sure these parts are correct as they show up as Scirocco / Corrado / Passat / Santana in ETKA. My current pedal is 3A2 721 509A; I believe the correct auto/RHD/cruise pedal is 3A2 721 509B (with actuator bracket 358 721 819). Sadly this pedal is obsolete and not produced by Classic Parts so I may still have to go it alone - however it gives me some confidence in how I was planning to do it! Not sure on the bracket yet, but at least if I can get hold of one of them I'll be able to line the gas pedal linkage up appropriately for the factor actuator position. Or I can do it freestyle! :)]

 

Stone

Edited December 11, 2012 by Stonejag

[Stonejag 10]

Have now tested everything except the cruise ECU, per the checklist here. All working fine and I have good vacuum. Took the ECU apart and only found one suspect joint so I reworked that plus a bunch of the other accessible parts, fingers crossed it'll play ball for now...

 

Going to tackle the bracketry tomorrow and see what I can come up with in CAD.

 

Stone

[Jim 2]

Neat - great effort! Look forward to seeing if this all works out.

[Stonejag 10]

Knocked up some CAD for a massively over-engineered bracket. Did the arm length by eye based on the available space between pedal and firewall, it may be a little on the short side but the vacuum actuator has tons of oomph so it should cope fine - if not I can always rotate the actuator slightly to increase the force it can apply. I got a little paranoid about stress concentrations so added some nice big radii just in case...

 

Managed to persuade one of the machine shop guys at work to cut me a couple out of 4mm mild steel in his lunchbreak :) Fingers crossed I can reach to drill the mounting holes in my existing pedal arm without removing it, access is quite tight but it looks doable. The OEM actuator bracket is still available but for 25 quid I'll make my own out of some angle iron! The arm that pulls on the throttle cable is a huge strip of steel (25+mm wide) so a couple of M5 holes shouldn't bother it too much. I also acquired some M5 dome nuts to tidy up the back of the bracket and stop anything catching on it - I'll probably hold it on with a nyloc first and then dome the rest of the bolt.

 

Should get my finished brackets later so I'll see how close I got on the first attempt :)

 

Stone

[Stonejag 10]

Got the bracket, going to prime and paint it this evening and hopefully tomorrow it will be dry enough to test-fit :)

 

 

By eye it will be a fair amount shorter than the arm shown in the ETKA diagrams, but that's intentional...

 

Stone

Edited December 13, 2012 by Stonejag

[dannyboy 0]

Nice to see some great engineering work my man! Keep it up and hope it works well for you!