ECM interface documentation
Thanks,
Jay
[Modified by JayH, 10:29 PM 4/28/2003]
[Modified by JayH, 10:30 PM 4/28/2003]
How about this then? Anyone know which flavor of chip is in the 94-95 models? I'm guessing its a motorola... 68HC11? MC68332? MC68HC58? Anyone even know if I disassembled the computer if the chip would have its designation printed on it?
Jay
[Modified by JayH, 7:08 PM 4/29/2003]
For what it's worth, the http://www.diy-efi.org archives have a few strands here and there about what you are talking about. I was on the list for a short time and it seemed that about that time, most of the PCM stuff started going underground cause someone took the public info shared and then made an editor with everyone elses ideas. I could be a little under-informed about that, but that is how I saw it.
Anyways, they have a search engine up if you poke around the diy-efi site and it might be able to help you out a bit more. Either that or give us a year...right now, it seems the majority of us are just getting into actual processor stuff instead of just standard bin editing. I for one am interested on the ECM data stream, cause I want to see how to strip some info in the stream and replace it with more meaningful data...either getting 2 times the capture rate on RPM and timing for example by taking out some flags that I don't use. It'll be a while for me. Good luck, -85Y
IIRC, for the Mass Air LT1's they are a GM version of the 68HC11F1. FLASH memory for OBDI is two AN28F512's. For OBDII it's one AN28F010 and one AN28F512.
These PCM's use two separate HC6811's, packaged separately (called "Event" and "Time" side) on their own boards. They are stacked together in the PCM case and communicate with each other over a serial bus.
Try a Google search for M68HC11RM.pdf. (It's the Motorola ref manual.) I notice there is a data sheet (MC68HC11F1.pdf) also on Google.
Also, check out this site (from the search)
http://pcm.dxsoftware.com/forum/YaBB.pl
Lots of good info.
Have fun,
Mike







