Ok, I’ve been looking around this board for a while, so now for my first post.
I am looking for a low cost off-the-shelf Vehicle to USB or RS232 adapter for the Low Speed GMLAN. At this time I do not wish to start from scratch and build my own interface, maybe in the future if my ideas pan out.
This is not an OBDII device, nor will any of the ELM based devices work.
Purpose is to explore the bus and operate a few items like the door locks. I have read of someone using only the CANHi side of a Two-Wire CAN to read the bus, but this was not a stable platform and sending commands sounded iffy.
On my vehicle the ECU, TCU, Brakes and Steering are on the 2-Wire Hi Speed GMLAN or “CAN” operating at 500kps. All other communications within the vehicle are on this Low Speed Single Wire CAN.
There’s been some recent activity on this forum regarding this SW CAN.
What I know: well think I know
GM’s “Low Speed GMLAN” is a Single Wire CAN operating at 33.33kps.
It conforms to SAE standard J2411 & GM standard GMW3089.
Its Higher Layer protocol is OSEK.
To help others wishing to develop a project the following CAN transceiver chips interface with it:
NXP AU5790 SEE IMPORTANT NOTE IN POST #34
Melexis TH8055 or 8056
On Semiconductor NCV7356
Anybody make what I am looking for?
My vehicle is a 2009 HHR.
It is my belief that all GM vehicles since ~2006 have both the Low and High Speed GMLANS, but what do I know.
I don't understand the "ICE" term.
However, I wish to intercept the door lock and unlock command from the remote receiver and the chime on and off commands.
I think that it's possible to use an ElmScan 5, by replacing the CAN transceiver with a SW version, and rewiring the pins to go to pin 1 of the J1962. Then you configure one of the user CAN protocols for 33k, and you should be good to go.
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You cannot send me a private message using this forum. Use my email instead: vitaliy[@]scantool.net.
* A review of the ELM product manuals from various manufacturers did not reveal a setting for 33.33K. The settings I found seemed to exclude this speed. Are you definitively saying this speed is available on an ELM product? I had earlier in my quest called ELM and they said it did not support what I was looking at doing. Or perhaps I worded my question to them incorrectly.
* Since I have been looking into this I have now generated a desire to have a good working unit for general OBDII use after this project and do not want to bugger up a perfectly good unit. I don't know about you, but my soldering skills to repeatedly solder a chip in and then back out seem to destroy pads.
* I am willing to spend a bit more for both capabilities in one product. So I am still looking around.
I notice you limited your suggestion to the ElmScan 5 and did not mention your newer product, whose name escapes me. Would it be capable of this as well?
ObdPro does a hardware mod that enables you to use the obdpro scantool to talk to the SW CAN. I'm having mine modded as we speak. Seems like there's almost enough demand to enable this by default...
Former author of LinuxICE, nghost, nobdy.
Current author of Automotive Message Broker (AMB).
Works on Tizen IVI. Does not represent anyone or anything but himself.