Saab OBD and Can-Bus
Sorry about the double post, but i was getting no responses in the newbie section.
I have browsing the net for a few months now, and I'm still not quite sure how i should go about this. I'm looking to get the most connectivity though my laptop to my 1999 Saab 9-5 SE 3.0 turbo. At first i thought having a connection to/with the OBD was neat, but i have learned you can do much more though the I-Bus and P-Bus.
Like i said i relay want to do it all or as much as this Saab will allow me to do, like reprogramming the ECU on the fly, check gas level, and find what my 0 to 60 time is. While I'm at it i might as well add a connection to connect to audio from laptop.
I know this sounds like a big project especially for some one posting a newbie section, but i think i can under take this during the summer, and finish up on some programs to take advantage of this.
My first problem i see, is that my OBD connector does not have pins for the CAN protocol (6 and 14). So what is the recommend solution? I was thinking about taping into the I-bus from audio head unit, climate control system, ore even the memory seat, and re rout it back to the OBD cable.
I have read about getting the I-bus signal from CD changer(have not found that connector yet in my car), but where can i pick up P-bus? Since pin 6 and 14 on the OBD connector is for CAN (which i want to use for I-Bus). Is there a way to tie in all the CAN protocol buses together, to read them from a single point?
Like i said I'm a newb to this car thing and may sound like I'm talking out of my ***. And that may be true, but I'm willing to read learn the proper way to connect my laptop to my car.
Hardware: I have noticed that the several OBD cables uses a Serial Port(RS-232) the problem with that my laptop does not have that connection. (How ever does have a 1394 FireWire, USB and Ethernet) I also looked at CANUSB dongle but those seem a bit pricey. Then i came along this http://www.obd2allinone.com/sc/details.asp?item=obd2usb
it seems perfect. Any thoughts?
I'm not yet worried about, after all i have a little programing background, and i have ran across some open source tools already.
But very open to suggestions
Any OBD interface will be limited to OBD functions only. Thats not much comapred to what data lies within the ECU and CAN bus.
Check out ECUProject.com - some cool stuff is happening over there.
Work is underway now to read (and write) ECU data through the CAN bus eliminating OBD altogether.
Have you seen Tomis site? Good stuff there too, mostly T7.
I am not sure what a 99 Saab supports but as far as an OBD II CAN interface goes take a look at what we offer at www.obdpros.com this one is one of the most reasonably priced interface and offers a slew of additional commands such as the ability to monitor the can bus and keep up with the full 500 KBit traffic with PC side speeds of upto 1.25 Mbits.
Are you in the US? I can check out the schematics for the Saab and let you know where the I bus and Pbus signals might be available
So even the cars with a contact for CAN on the OBD plug only has access to the same stuff just use a CAN protocol?
Originally Posted by hstanton
when you say Tomis, you mean http://pikkupossu.1g.fi/tomi/tomi.html#?
So if i OBDPro USB Scantool, i still would not be able to have all the control that the I-bus, since my OBD connector does not have CAN on it. But would it work if i add the CAN connections to the OBD plug? Or would i still need to buy something like this
Originally Posted by michbound
Yes I am in the US, and very much will appreciate where i can get the P and I Bus
From what I understand, OBD is OBD no matter what bus its transmitted over. Some buses are faster than others, as is the hardware that reads them.
Yes thats the site, smart dude he is.
You can tap the I-bus at the Cd-changer, Tomis site shows this.
The P-bus can be tapped at the SFI test connector thats located next to the ECU, courtesy of T5Suite documentation. Note that this info. is for 9-3/900, not 9-5 specific. Should get you going in right direction though.
Lawicels CANUSB seems to be the product of choice right now.
I'll add that the CAN bus stuff is bleeding edge, OBD is here now and Paul has a good rep for helping people out.