Actually I don't think it's possible to precisely match them with normal PC hardware, but my understanding is that as long as you're close enough to get through 10 bits (start, 8 data, stop) without jumping a bit boundary, that's good enough. I'm not sure what HyperTerminal is capable of, but 8192 and 160 are very non-standard baud rates. I'm a Linux-only shop here, I don't think I even have a Windows install CD. Maybe try stuff in HyperTerminal on Windows? Easier to mess with settings there to verify that it's correct. If anyone is really interested in this, I can post more details of what I've tried, code, etc. So, I thought I would give this place a shot. I know there's a lot of data out there about this stuff - believe me, I've looked at a lot of it - but it's kind of a random jumble and it's hard to find what you're looking for. I don't understand why the frame length would ever vary, as everything I've seen suggests that it doesn't. All of this is with the engine off, key in the RUN position. Other times I get more data following that sequence. Sometimes I'll get two of those in a row, like there was one whole frame that was nothing but that.

The weird thing is, I keep getting this byte pattern out of it: I'm assuming it's transmitting at the newer 8192 baud rate rather than 160 baud, but that's just speculation. I've been messing around with this today and data is flowing, but I can't figure out if I have the proper baud rate working or if I'm just getting junk data. Since I don't think my particular ECM is supported by any of the Windows-based software packages anyway, I figured I would try to write my own Linux program to get data from it. So, I have here an old Thinkpad and a USB ALDL cable that came from.

Aldl gm software reprogram