If you have a Citroen C3 Mk1 facelift (2006-2009) then you can find the 'How to install cruise control' for the facelift models here.
If you just want to know what's involved in removing the steering wheel airbag and/or COM2000, this also may be of interest.
This post is mostly the same as another post on how to remove the steering wheel and COMs unit over here
But I had taken all the photos before I realized the other post existed. Just to make the post comprehensive I'm including the photos and instructions. Sigh.
To my knowledge all of the engine ECU variants are capable of cruise control.
Also, to my knowledge, Cruise control was not offered as an option in Australia (where I live). I have no idea who makes decisions about which models make it to our shores. Most of the bits I got from Ebay in the UK.
There are a number of ECUs involved in the process of Keeping the car running autonomously at a predetermined speed. The major one is the engine ECU. Effectively it takes information off the 'CAN' network to regulate the engine power and RPM. On this CAN network is information such as the speed the car is going and requests from the driver, like "speed up" and "slow down" from the cruise control buttons. There is a lot of information traveling across this network and those are just a few things used by the engine ECU.
A couple of the other ECUs involved are the COMs unit (the indicator stalks), the BSI (does the coordinating) and the ABS ECU. The ABS ECU sends out the speed information and the indicator stalks ECU manages some of the requests from the driver.
You will need the steering wheel with the controls in it, the correct COM2000, some information about the clutch switch (I'll get to that in a minute) and a LEXIA configurator.
Now the clutch switch might be optional, stick with me here. I bought two C3 automatics. One came with the clutch switch installed and one without. WTF do you need a clutch switch in an auto? Well the clutch switch is connected to the engine ECU and that tells the engine ECU if the clutch has been depressed. If you were in a manual and the cruise control was on, depressing the clutch would cause the cruise control to drop out. Yes, but what about an auto? Well, why did they install the switch at the factory? I don't know. I had two choices remove the switch...or not! It sits way up on top of the peddle box, so getting to it is a pain either way. All things considered just see if your car has the clutch switch installed and we will move on from there. Just keep it in mind for later...it will become important.
After that we need to remove the steering wheel airbag. On each side of the steering wheel hub is a hole. Inserting a screw driver into the hole will release the retaining wire for the airbag. Pull the airbag off. It is held on by a farther three plastic lugs but the airbag will eventually come off. The air bag is connected to the steering wheel by three electrical connectors so don't attempt to pull the airbag completely off just yet. Remove the airbag electrical connector by pulling the yellow clip outwards, then removing the whole black connector. Remove the two connectors going to the horn contacts.
Remove the bolt holding the steering wheel onto the steering shaft. Wiggle the steering wheel left to right to loosen it off the shaft.
If your car has 'ESP' I wouldn't recommend going any farther unless you know what you are doing. If you remove the COMs unit on a car with ESP the alignment of the COMS and front road Wheels needs to be carried out after re-installation of the Coms (unless you are very lucky) and I am not going to cover that here.
The Com2000 needs to have a three pin connector coming out from the center hub.
If you get a flappy paddle COM2000 for the right price, it is possible to remove the paddles and install it in a "regular" COM2000 spot. This is what I did...but my plans came unglued!!
It may be that you already have the correct COM2000, if you are lucky.
If you need to replace your COMs unit, remove the two screws holding the upper and lower shrouds to the COMs and steering column. Remove the lower shroud.
Now connect the "new" COMs unit to the electrical connectors on the wiring harness. Holding the clamp in place, slide the COMs into place on the steering column until the two plastic clips click into place.
Install the lower shroud onto the upper shroud and COMs unit with the two screws. Take your time with this as the shrouds need to line up correctly with the COMs and each other to fit correctly. There is also a hook on the bottom of the steering column that fits into a cut out in the lower shroud.
Once you are happy that the COMs and the upper and lower shrouds are in position and secure, install the steering wheel and steering wheel retaining bolt. There is a single large tooth in the spline on the steering shaft that has a matching gap in the spline of the steering wheel so that the steering wheel and shaft are lined up correctly.
You can then connect the three way connector to the steering wheel cruise control switch connector.
Connect the two horn connections. There is one large spade connection and one small spade connection.
Line the airbag up on the three locators on the steering wheel and push the airbag all the way home.
Now we start configuring the system and telling the relevant ECUs that we now have cruise control.
In case you don't know the 'LEXIA' is (was?) Citroen's scan tool, used to talk to your car. It provides information and allows you to configure parameters for servicing or modifying your car. Almost mandatory for doing your own work on your car these days.
It runs on a PC or laptop and has an interface that plugs into the 'OBD' port in the glove box.
Like a lot of computer programs configuration involves navigating through a series of menus to get to the 'switches' required to select the option you need.
Most of the servicing you will do in the LEXIA is done under 'diagnostics'
The first place I'm going to go is configure the engine ECU, a SAGEM S2000PM1.
Next up is configuring the BSI. This is the brains of the car and sits in the glove box.
At this point you should be ready to take the car for a run and see if the cruise control works!!
With the ignition on, each time the cruise control on/off switch is set to 'on', you should hear an audible "ding". Nothing happens when you turn the cruise control off.
It was at this point that my installation went pear-shaped!
when I turned the ignition key to start the engine, it turned over but the car wouldn't run. WTF!
OH S***T!! Have I reset the engine key programming some how? I do not have the engine PIN code and cannot reset the keys!!!! OH CRAP!
The cruise control buttons worked in LEXIA and if I moved the control stalks they worked too. So the COMs unit was working (it seemed). @#$%! There was one other clue, the central locking didn't work. The RFID chip and central locking transmitter in the key are inexorable linked by magic unicorn dust only understood by Citroen, so it's possible the key codes have been lost! Then again, the central locking receiver sits in the top of the COMs unit and I just changed that! However the RFID coil sits around the key lock barrel and I did not change that. Could the RF module run the key RFID too? I didn't have much of a choice, the only major component I changed was the COMs unit and the only thing I could try was re-installing the old COMs unit, so I reinstalled the old COMs unit and attempted to start the car...it started and ran!!! PHEW! Ok so what went wrong? On the surface it seems the RF module in the "new" COMS unit is faulty but I cannot prove that. It is possible it's running a different frequency/protocol but either way it's not working with my key.
The RF (radio frequency) module sits in the top of the COMs unit and plugs into the main board via a 4 pin electrical connector.
What now? Well the front face of the COMs unit connects to the steering wheel airbag, horn and cruise control switches via what is called a "clock spring" connection. Effectively its just a ribbon of wires wound loosely around a bobbin in the center of the hub. It's this front face that has the extra connector needed for the cruise control switches.
Ok, so after all that I now have cruise control in my car! One other thing I want to investigate is installing the "pod" style of cruise control switches, used in the MK2 cars, in the MK1 COMs unit. There are BIG physical and electrical difference between the MK1 and MK2 COMs units and they are NOT interchangeable!! I noticed that the "flappy paddle" version of the MK1 COMs mother board has an edge connector that the pod style of switches might fit into!? The steering wheel style of cruise control switches for the MK1 cars are becoming very rare (and expensive) these days but the pod switches are easy to find. Stay tuned!
Hi there! Ozvtr from the future here, with a bit of an update.
For the cruse control to work you need to have a "fly-by-wire" throttle body. It has been brought to my attention that there are push-pull cable versions of the throttle body on some 1.4L TU3 engines. This mod wont work with them.
The clutch switch. This is only required on a manual transmission car. If you install and activate it with LEXIA on a auto or sensodrive transmission you will get an error saying the switch may be faulty as it has not changed state for a while!! So set switch "not present" for an auto box.
