Citroen C3 Gear Knob Displacement

As I promised last week, here is the details of my biggest and most meaningless modification: Re-positioning the gear knob on my Citroen C3.

First of all I should mention that this was done in 2007 and unfortunately I did not document the things that I have done properly, so there will be a lot of writing. At least there is video of the working system at the end.

Secondly here is a brief explanation the vehicle: It was a blue 2005 Citroen C3 1.4i sensodrive. Among this definition the only important factor for this project is the "sensodrive" function. This means that the vehicle has a kind of automatic transmission. However it is different than regular automatic transmission.

Now I'll just give some information on kinds of transmissions. If you know these or you don't care about them, simply skip the next 3 paragraphs :)

Cars with manual transmission have a clutch pedal to separate the power of the engine from the wheels. One can change the gear only by manually pushing the clutch pedal.

Where as in a regular automatic transmission, instead of the clutch system there is a torque converter which probably somehow converts torque. As you can see I don't know much about how it works, the only thing I know is that it uses transmission fluid and pressure to connect and separate the engine power and wheels. When compared to the manual transmission this is much more complex. In this case driver does not do anything to change the gears, the whole operation is handled by the car's electronics. The gear knob in these cars have P (park-which physically puts a solid gear in the transmission to block it), R (reverse), N (neutral) and D (drive). Because the so called torque converter does not separate the power completely, when you put it to Drive, even before you hit the accelerator the car tends to roll so you have to push brake to stop it.

Finally my kind: Sensodrive (semi-automatic). The mechanical system of this kind very similar to manual transmission. There is no clutch pedal to operate but there is a clutch that is controlled by the electronics. Many car companies have a similar system (Peugeot: Auto6R, Volkswagen: DSG, Renault: EDC, Opel: Easytronic...). The system is being updated regularly but the main draw back is the shaky gear changes. In these cars usually there is no Park gear and they don't move by themselves when you put it to Drive (except for DSG: it imitates the regular automatic transmission electronically).


As long as my project is concerned, the only important criteria is that the gear knobs on manual and automatic transmissions have physical connections with the transmission but semi-automatic ones does not. So their gear knobs are only a set of switches to give proper commands to the electronics.

This is where I enter :)

Citroen's gear knob had N, R, (+) and (-). You had to put it to Neutral to start, and (+) to put it to drive. While driving if you hit (+) it would change to manual mode and you take control of the gears. To put it back to automatic there was a separate Auto button.

One day I was disassembling the car to see if I can modify something (yes, this is regular activity for me) and I realized that the gear knob had a 5 pin input. Since it had only 4 functions I assumed that there was a switch for each function and a common ground connector.

Initially I hesitated to open up the gear knob box because Citroen guys did not want it to be opened so they used rivets. One weekend my wife was on a business trip (this is important because rightfully she was against this operation due to the not so small probability of messing up our only car) and just as a coincidence I was alone in the house with the gear knob. By the help of an electric drill I cut the rivets off and there it was:

This is my control card to imitate the gear switch
and operate power windows

The electronics of the knob were simple, only 4 buttons however the by using complicated pieces and springs they were working in pairs. So for the command (+), buttons 1 and 2 should be pressed; for (-), buttons 3 and 4; for Neutral, buttons 1 and 3. Reverse was a bit complicated because to be able to ensure that the transmission is in Neutral before trying to engage Reverse, Citroen engineers did a trick. For the Reverse command you had to press buttons 1 and 3 (this is Neutral) and after a split second while holding on to button 1, you should let go of 3 and press button 4. Since I wanted to get rid of the gear knob, all I had to do was to copy these moves with my own electronics.

My first idea for gear buttons

Once the electronics were done the next step was to find where to put the new buttons. My initial plan was to place them to the middle console like in a Maserati GranTurismo but then I had a better choice. I got hold of a broken middle console switch set for a Mini Cooper. There was a problem with the inside electronics but the switches were working fine. I connected the switches to the commands of my electronic card ant it worked great. Mini part fitted the empty slot below the stereo perfectly.

 

Repaired and modified MINI Cooper switches

Other than the gears I connected the window buttons and auto-shift switch to the respective buttons and it was all done. The beauty about it was that the auto button also had a light on it, indicating if its in auto mode or not, so I connected it to the former switch of fog light which had a light on the tip of the switch.

Final look of the middle console

Here is the video of the working system. You can hear the gears changing as I push the buttons.

Work in progress concole

My next step was to find something to do with the area between the front seats. At this stage my wife was on board with the idea and we decided to construct a console with a deep cup holder that is connected to the car's air conditioning system. It was supposed to be used as a cooler for our drinks in the summer or a baby milk warmer for our 3 months old boy in the winter. I also wanted a 5V USB charger and a 220V socket using an inverter on the new console. I was planning to use the final switch on the Mini Cooper switch panel to activate the 220V. I constructed a mock-up using plexiglass and wood. Everything was functional except for the 220V socket.

At this stage, before I had a chance to construct the final middle console from fiberglass, we had the great news that our second son is on the way. Since we could hardly fit C3's boot with a single baby, we decided to upgrade to a C4 Grand Picasso.

During this modification I was very careful not to do anything irreversible, I just put the original parts of the car back and sold it. Of course it was touching to let go of a vehicle after spending long hours in it but the excitement of the brand new car was overwhelming.

I drove the car like this for about a year with no problems. I don't know how the idea first got into my mind but I ended up spending days or even weeks on it. It was only as practical as its original but much more cooler. I had great fun with the valet parking as well. The valets always remembered me when I got back :)

Thanks for your patience..
The next entry will be a useful one: Repairing a Renault Card Key that does not start the car.