D8 Cruise Control Retrofit

[plod]

I guess I need to find another D8 HDi that has cruise and see what the set up is

Hope I'm wrong, but I suspect there's no such animal.

me too

[jonsowman]

Two D8s in the scrapyard, a 1.9 and a 2.1, but both LX's and neither had cruise. Never mind.

As soon as the weather clears up a bit I'll remove the wheel and arch liner from mine to examine the wiring.

[jonsowman]

Right, I had an hour today in which it wasn't raining/thundery, so off came the wheel and in short, both connectors (for the vac pump and the solenoid) are there!

I'd need axle stands if I were going to mount the vac pump as I'd need to get properly under the car. I couldn't see the mounting point for the pump but I'm sure it's there.

I think the next thing to do is get the vac actuator and bracket and see if I can work out how to mount it, with its connection to the throttle pot.

Any thoughts etc welcome

The solenoid cable:


The vac pump cable:

[Doggy]

That looks encouraging. Are you thinking the D8 diesel cruise system is the same as the petrol models?

[jonsowman]

That looks encouraging. Are you thinking the D8 diesel cruise system is the same as the petrol models?

I think so, yes. My reasoning for this is mostly because ServiceBox says so -- the part numbers for the 2.1TD cruise system match up with those for the 3.0 V6 system. Additionally, it would make sense for Peugeot to use the same system, in financial terms. I was thinking that the Lucas Epic system might have had electronically controlled cruise, but the ServiceBox information, and presence of the wiring for the vac pump and solenoid indicate the opposite. Certainly I think the vacuum operated system will work fine on the 2.1, if I can find a way to mount the actuator ("official" or otherwise).

I really need to get some pictures of a 2.1TD with cruise, but I still can't find one anywhere

[midsmike]

got u some pics of the v6 will upload them later what does the ecu look like ive took all the boxes from under the glove box off i just dont no wat 1 it is lol

[jonsowman]

got u some pics of the v6 will upload them later what does the ecu look like ive took all the boxes from under the glove box off i just dont no wat 1 it is lol

Brilliant, thanks mate. I will probably want all the bits from you, just doing a bit more investigating first.

Here are a couple of pics of the ECU from the Coupe club thread:



The ServiceBox part number is 6660.54 if it happens to have that written on it.

[RayneR]

cruise stalk its the same as the early d9 like mine and it's from a 406 coupe, so this can help you to find it easily.

Saw the pics that u uploaded, that's great findings so you have everything for cruise, and u could confirm that the same equipment is fitted to the 2.1 td. Now i can agree with you and try buy the petrol parts.

Hope you sort it out mate!

[jonsowman]

Bit of an update for you (apologies for long post). I've been looking around French forums for the Xantia and the XM using a combination of Google Translate and A-Level French These cars were both fitted with the 2.1TD XUD engine and there are a couple of extensive threads on fitting cruise:

http://www.planete-citroen.com/forum/sh ... hp?t=34803
http://www.planete-citroen.com/forum/sh ... hp?t=57447

It comes down to the fact that the cruise system is not in fact vacuum operated on the Lucas EPIC system, but is in fact entirely controlled by the injection ECU. The following diagram is particularly relevant:


To translate:

Pin 1) Brake/clutch pedal switches (wired in series)
Pin 28) Memorise/increase speed
Pin 29) Cancel cruise
Pin 32) Decrease speed

It seems that all signals idle low with +12V signalling when required, with the exception of the pedal switches attached to pin 1, which must idle high (+12V) and fall low on press of either switch.

So I went out to my car and had a look, and the good news is that the wiring for the clutch and brake pedal switches exists:
Clutch:


Brake:


Now, the bad news. The ECU connector has none of the required connectors in place for the above 4 control signals. Here's my ECU connector (same orientation as above):


So, if I'm going to install cruise I'm going to have to put this wiring in place. The question is how much of it exists in the car, and where and what I can splice onto. The connector for the cruise stalk is a white thing under the steering column, and it does have 5 wires leaving it, as it should (3 control signals, 12V and GND - I think!):


These cables join into a loom and go through the bulkhead, after which they disappear into the offside wing behind the PAS fluid reservoir. I'm going to have to remove the wheel arch liner to see where they go. Alternatively I can not use the existing wiring, and do everything from scratch.

Another good bit about the Lucas system is that the only parts I need are the control stalk and pedal switches. I think I also need the cruise enable button as it supplies power to the stalk when turned on. I don't need the cruise ECU, vac pump, solenoid or vac actuator, which makes this a lot cheaper. So I'm going to get the bits and investigate further

Here's a wiring diagram someone has put together on the Xantia forum for the Lucas cruise system:


Translations:
Comodo: cruise control stalk
Interrupteur: cruise enable button
Capteur frein: brake pedal switch
Capteur embrayage: clutch pedal switch

For reference, here's the cruise wiring diagram from a petrol D8: http://img161.imageshack.us/img161/4711 ... ncerf1.jpg

So, that's where I've got to. I'm going to try and complete this, since it's not too much effort (comparable to my trip computer retrofit). I will of course keep you up to date on progress The only downside is that this is now only useful for the 2.1, totally useless for the petrol models and the 1.9 XUD, since they both involve mechanical actuation of the throttle or Bosch fuel pump.

[lozz]

You will most probs need a wiring diagram to work that lot out,
good luck with getting it all working
http://peugeot.mainspot.net/wiring406/p8c.shtml

[jonsowman]

Thank you!

From those diagrams it appears that I do need the cruise enable switch (I've updated one of the above diagrams with a better one). When pressed it supplies 12V to the cruise stalk, which can then pass voltage onto the control pins of the injection ECU.

The difficult bits are going to be routing 4 cables from the ECU into the cabin - does anyone have any advice on this? And also connecting up the brake and clutch switches.

I'm going to get all the parts and then do some prodding with a multimeter to see how things are wired up.

[Doggy]

Formidable!

I'm guessing direct information on a 406 2.1 TD with cruise would be even better - have you tried the french 406 forum, http://www.passion-406.com?

I'm on there a bit and can try posting something for you, but you may prefer the direct approach, (I suspect your french is probably better than mine anyway).

They're a reasonably friendly bunch, but do like you to observe their protocols, (read the instructions, introduce yourself first, start a thread on your car, etc).

Let me know if you want me to try

[midsmike]

so is it a case of plug and play i might see if i have the pins in my 2.1 and if so might hav ago

[jonsowman]

Let me know if you want me to try

If you don't mind, that would be great, mainly because you're already known on the forum. I've had a quick search and can't find anything related to fitting cruise on the Lucas system.

Very kind of you to offer, thanks a lot

midsmike: Pull the injection ECU connector off and see if those wires exist. If they do, then for the Xantias/XMs it means the car is entirely wired for cruise. You just need to plug in the stalk, enable button, and the pedal switches, and away you go. I wouldn't be surprised if the same is true on the 406. I think plugging stuff in is the easiest way to find out though!

Mine hasn't got the cruise wiring, but I appear to be the first person who's investigated this on the 2.1 406. Therefore I can't really say whether any others have the wiring. If you could check yours, that'd be great, especially since it's an exec.

[Doggy]

The difficult bits are going to be routing 4 cables from the ECU into the cabin - does anyone have any advice on this? And also connecting up the brake and clutch switches.

Not sure if your D8's the same, but I found a convenient grommet close to where the steering column goes through the bulkhead. Pull the upper edge of the carpet back a bit (in line with the brake pedal IIRC) & you should be able to feel it about 3" down from the top of the carpet. It's visible from under the bonnet too, but difficult to reach.

If you don't mind, that would be great

Consider it botched.