Can bus messages. SOS

**EOdOW** · 11-12-2009, 10:03 AM

Hi there!
Im trying to create an alarm system that should work off of the CAN bus.
I need help in interperting CAN messages, any info would help. May be some one can point me in the right direction on where to look. THis is the best info i have found so far http://pikkupossu.1g.fi/tomi/projects/i-bus/i-bus.html

Thanks to all in advance.

**p2psmurf** · 11-12-2009, 02:08 PM

Every manufacturer uses his own standard for messages on the Can-bus. Besides a few id's defined for OBD2/EOBD/JOBD everything is free and so is the format.
So, you need to reverse engineer the messages for each and every make.
Still interested?

**EOdOW** · 11-13-2009, 03:34 AM

Oh yes im still interested, but I am afraid i do not have the time to reverse engineer the messages. Where can i get the message id's that you said are free?

**p2psmurf** · 11-14-2009, 03:12 AM

Nowhere. And even if you're willing to pay big bucks there not available.

**Vitaliy** · 11-16-2009, 07:48 PM

I think this is the confusing part:

Originally Posted by p2psmurf

Besides a few id's defined for OBD2/EOBD/JOBD everything is free and so is the format.

Don't you mean "proprietary", and not "free"?

**p2psmurf** · 11-17-2009, 02:51 AM

Mea Culpa. With free I meant to say not governed by any regulation or in other words proprietary or manufacturer specific. I did not meant to say that you can get these descriptions without paying, if you can get them at all.

**Crinos** · 11-17-2009, 04:14 AM

My first place to start would be at the car dealership. Ask them if you could get the codes, and even tell them why.

Some dealerships are very helpful in such matters, and others, well... They probably should be doing something else in their lives than sell cars.

**justchat_1** · 11-17-2009, 02:18 PM

The manufacturers charge between 5K and 20K per year for access to the latest codes. Not only do the dealerships not have this information, they would never give it to you for less then that price.

**Crinos** · 11-17-2009, 03:19 PM

That have never been an issue for me... I have had several BMWs that I have modified in one way or another, and the local Bavaria have been extreemely helpfull.

Ofcourse, if you ask a question your local shop cannot answer. They might take a charge for the servcie.

**justchat_1** · 11-17-2009, 06:50 PM

Originally Posted by Crinos

That have never been an issue for me... I have had several BMWs that I have modified in one way or another, and the local Bavaria have been extreemely helpfull.

Ofcourse, if you ask a question your local shop cannot answer. They might take a charge for the servcie.

So you have asked your local shop for manufacturer specific codes and they gave them to you?