Technical CAN BUS Speed for wires behind the radio

[joeyCV93]

Hey Guys, this is my first time posting on the forum after a good few months of lurking. Unfortunately i feel i have to ask this question as i am now stumped after finding lots of conflicting/unclear/maybe i just don't get it properly information. Sorry if this is a little long but i'm trying to be thorough in explaining my problem.

As a project for univeristy i am currently making a GPS/Data-logging device using an Arduino MEGA and a CAN Bus shield from Sparkfun (DEV10039 - Retired)

(I tried to link a URL to this shield but i can't 'cos i'm a n00b )

With the intention of grabbing RPM, speed and engine coolant temperature and displaying it on a screen/Writing to an SD Card.

I have a DB9 to OBD-II cable but failing being able to use this i also have soldered wires to the CAN H and CAN L sockets on the aformentioned shield with the intention of using the Pink/White and Pink/Black CAN wires behind the radio.

After lots and lots of head-scratching and fruitless googling i have found that my Punto (A 1.2 8v Active Mk2b '54 plate) uses the Keyword 2000 protocol along with CAN Bus. The problem i am facing is that i do not know what speed the CAN buses on this model of Punto runs at, or if the wires behind the radio are the same speed as the CAN H/L sockets on the OBD-II port.

I had found that it was 500Kbps for the Hi-speed CAN on OBD Port pins 6 and 14, but upon testing my device the car either didn't start and flashed its petrol light at me a few times or brought up the steering and ABS warning lights when the engine was running.

In all cases i received no data over my CAN Bus shield when trying 125, 250 and 500 Kbps speeds conencted to the OBD-II port.

To reiterate i am hoping that someone on this forum has experience interfacing with the CAN bus on this model of Punto and can tell me:

• The Speeds that the CAN Bus(es) on this vehicle runs at.
• Whether the CAN Bus wiring behind the radio is the same speed and bus as the one connected to the OBD-II Port.
• Any other information that they feel may aid me in getting data from my car.

Thankyou for your time.

 

[g8rpi]

Hi welcom to FF,
Sorry you are having issues. I can't help with firm information on the radio CAN bus (but will give some assumptions further down

) It would probably be better to stick with the OBD port if possible becuse it's more universal. I've looked at the shield info https://www.sparkfun.com/products/retired/10039 and it has a design fault which may be part of your issues. The fault is quite a common one, they have fitted termination resistors across the bus connections. There should be only two terminators on a CAN bus and both are already fitted to the car. The components on the shield are R10 and R12, C2 and C3. Remove either both resistors, or both capacitors. Also don't use a long cable to connect the shield to the car, no more than about a metre, preferably twisted screened pair.
On the radio bus, thi is not part of the main car system and may not have all the data you need and could be non-standard. You can determine the speed by looking at the data bus with an a oscilloscope.

Robert G8RPI.

 

[aFiFi]

dear friend i'm having trouble with the can network on my 188 1.2 8v 2001 when i messed with the behind radio cables while trying to setup my cd player ..
the dashboard is flashing lights and i get no info out of it
it tries to reconnect but no good .
plz help me i'm feeling down with the issue

 

[g8rpi]

dear friend i'm having trouble with the can network on my 188 1.2 8v 2001 when i messed with the behind radio cables while trying to setup my cd player ..
the dashboard is flashing lights and i get no info out of it
it tries to reconnect but no good .
plz help me i'm feeling down with the issue

Hi,
While I understand you are trying to fix your radio issue, posting the same question to multiple threads tat are not relevant(e.g. radio CANBUS speed) does not help.
People will just ignore your posts as they cannon follow what answers have been given on other posts.


It is very difficult for us to remotely diagnose what you have done to your car. Language difficulties don't help, but I think you need to get a local specialist on the problem.


Robert G8RPI.

 

[aFiFi]

Hi,
While I understand you are trying to fix your radio issue, posting the same question to multiple threads tat are not relevant(e.g. radio CANBUS speed) does not help.
People will just ignore your posts as they cannon follow what answers have been given on other posts.


It is very difficult for us to remotely diagnose what you have done to your car. Language difficulties don't help, but I think you need to get a local specialist on the problem.


Robert G8RPI.

i'm just trying to find some answers might help me with the issue is all ,
and its relevant to the can bus cables

 

[Eklipze3k]

i'm just trying to find some answers might help me with the issue is all ,
and its relevant to the can bus cables

So do the research first, then post a single thread with all the diagnostics you've done so far. As above, it's much easier for everyone involved if there's only one thread to look at which has all the information in it.

 

[aFiFi]

So do the research first, then post a single thread with all the diagnostics you've done so far. As above, it's much easier for everyone involved if there's only one thread to look at which has all the information in it.

this is a part of the research , and I've already posted a thread with the issue

never less , if you don't like any comments , just don't put your mind to it ,

its a free world

 

[PuntoHowTo]

So do the research first, then post a single thread with all the diagnostics you've done so far. As above, it's much easier for everyone involved if there's only one thread to look at which has all the information in it.

never less , if you don't like any comments , just don't put your mind to it ,



its a free world

Eklipze3k is a moderator of the forum. If he is telling you what to do, it is very strongly advised you listen.

If you keep posting the same question repeatedly all over the forum and not listen to the advise of the moderators, your time on the forum will be very short lived and you'll end up getting no help