Thread: Onstar GMLan & CAN bus GPS hacking

In addition to setting the baud rate to 33 kbit/s you will need additional hardware to work with SW CAN.

GridConnect sells an adapter for $170:

http://www.gridconnect.com/au5790.html

Or you can roll your own using a "normal" CAN transceiver (e.g., MCP2551) and a SW CAN transceiver chip (e.g., NCV7356). Total parts cost <$10.

Notice that GridConnect's adapter will not work with ElmScan 5 or OBDLink out of the box (the pinout is different).

Best regards,

Vitaliy

Thanks Vitality for the good info.

I wish I had the smarts to make that circuit.

If you are looking to view SW can data you can also look up the Peak Systems (PCAN-AU5790) device. This will convert SW CAN to Dual Wire and DW CAN to SW.

You can find out if you car has GPS over CAN by looking at the OBD II connector and try to find PIN 1. This is typically in the top left of the connector (PIN 1 is at the left of the wider part of the connector).

If there is something there, then you have SW CAN. If you see something in PIN 2 (just right of PIN 1). Then your car uses J1850 (aka Class 2). Of course you car has to be equipped with OnStar as well.

Good Luck.

The ELM327 can be configured and wired to communicate on the GMLAN bus.

see my notes and pictures at: www.gtosoft.com under "coming soon".

Just wanted to follow up so nobody spins their wheels

Some samples of how GMLAN can be used to control stuff from Android phone:

http://www.youtube.com/user/gtosoft

I modified a few DX adapters for use on SWCAN network:
http://cgi.ebay.com/ebaymotors/ws/eB...m=260663848162

Hi
Do U know where I can get the gap: URL scheme/protocol
specification/ABNF/rules ?
I'm implementing a server and need to differenciate
between valid/invalid URLs.
thx