2004 Petrol Can Bus help

Hi I have a 2004 Citroen C3 Exclusive 1.6 16v.

Its a Brazilian plate, but at that time, the car was still being imported from France. Not sure how it translate to the plates/models that were available in Europe at the time. I can provide more information if needed (Lexia available).

I'am trying to read data from the can bus network, and I was able to use an arduino and a can bus shield to sniff the traffic. I have not tried to reverse engineer it yet so I have no idea if the data there is valid or not.

Doing some research I got in doubt if this vehicle is indeed CANBUS or was still using VANBUS.

Any help on identifying the kind of network use is really appreciated.

Final goal is to identify both running information (like rpm, map, maf, temperatures an etc) as well as other non-obi available (like if aircon is on, door open, lights on and etc).

Thanks in advance.

Hi joboehl

I did see your topic in the club area and it sounds like an interesting project .
c3-owners-club/my-c3-project-t1911.html

joboehl wrote:Doing some research I got in doubt if this vehicle is indeed CANBUS or was still using VANBUS.

I think you will find 2004 is mostly or all VAN, you need to get to 2006 at least for a full CAN system.

joboehl wrote:Final goal is to identify both running information (like rpm, map, maf, temperatures an etc)

These are from the engine ECU and you should be able to tap into the Engine ECU via KWP2000. I know you can on a Diesel VAN C3.

joboehl wrote:as well as other non-obi available (like if aircon is on, door open, lights on and etc).

Available in Lexia, they are all available in the BSI.

C3driver52 wrote: I did see your topic in the club area and it sounds like an interesting project .
My Citroen C3 Project

Thanks!!!!

I think you will find 2004 is mostly or all VAN, you need to get to 2006 at least for a full CAN system.

Thats what I was afraid of. Well, will see if treating it like CAN bus have any meaningful use, at least from a reading perspective. Thanks very much, this information helps filter a lot of CAN bus related information that probably won't make sense on VANBUS.

These are from the engine ECU and you should be able to tap into the Engine ECU via KWP2000. I know you can on a Diesel VAN Citroen C3.

Thanks for the link!!! Would KP2000 give me more information/control compared to OBD? I already use OBD to collect some information, although the number of available PIDS on the car at that time were really limited.

Available in Lexia, they are all available in the BSI.

Yes, Lexia shows a LOT of information, and clearly is flowing trough the OBD-like connector. That gives me hope that is somehow possible to get that information.

Problem is I need some programatic way to get that. I was hoping can bus/van bus would be a way of doing it.

Thanks very much for the info's.

joboehl wrote:Thats what I was afraid of. Well, will see if treating it like CAN bus have any meaningful use, at least from a reading perspective.

You need to treat it like VAN to be meaningful.

At the media layer, VAN is a differential bus with dominant and recessive states signalling ones and zeros much like CAN bus. The data is encoded using 'Enhanced Manchester' which sets it apart from almost every other line signalling protocol.

https://en.wikipedia.org/wiki/Vehicle_Area_Network

joboehl wrote:Thanks for the link!!! Would KP2000 give me more information/control compared to OBD? I already use OBD to collect some information, although the number of available PIDS on the car at that time were really limited.

You can talk directly to the engine ECU on the K line of KWP2000. I have not tried it on a petrol, so have a go and see what you can find in the Engine ECU. Its good you managed to get some with OBD, there must be some CAN on the early C3. They get called CAN/VAN for a reason . Use lexia for the full array of protocol options to cover all the sensors.

joboehl wrote:Problem is I need some programatic way to get that. I was hoping can bus/van bus would be a way of doing it.

The connector looks like an OBD connector, but the pins are wrong and is not fully CAN compliant on early cars. You need to use different protocols to communicate with the various systems of the car. So you will be doing exactly what lexia does and switch protocols as it scans different ECUs.
There is a preview of the VAN ISO protocol information https://www.iso.org/obp/ui/#iso:std:iso ... ed-1:v1:en
and the full one is for sale https://www.iso.org/iso/iso_catalogue/ca ... mber=19471 as a PDF, so I am sure some searching would bring up some VAN protocol information.