PIC to GM E&C protocol

[dyeatman]

I am starting a PIC to GM E&C protocol interface project using CCS C.

I know the basics about the protocol (SPI, bits, speed etc) but no info on the protocol command details. Anyone here have the info or point me to detailed documentation before I have to work it out on my own?

When it is complete I will post the code in the library.

Any info wopuld be a great help!

[mkent]

Hello Dyeatman,
I did some searching on this subject without much luck. The diagnostic codes are availble, but to do any modifications of parameters is another story. This may be due to EPA; they don't want you messing with the emission controls. Check this site: http://carputing.tripod.com/LS1main.htm
It is the only software I found that allows modifing parameters.
I hope this helps a little. Mick

[dyeatman]

Thanks for the info Mick,

The E&C (entertainment and comfort) is separate from the ECM (engine control) system which is SAE J1850 protocol (known as OBDII). Actually, the J1850 part I already have working pretty well. It obtains real time engine diagnostics info and displays it on my IPAQ 5550 mounted in my car.

Now I am wanting to decode the 1-wire E&C radio changer data output with a PIC to provide control output signals in response to my steering wheel radio controls. I plan to control MP3 players, changers, custom car controls etc and also feed back messages to be displayed on the radio display.

Dave

[iso9001]

I looked for some info on E&C.

I found some info on that may or may not be of any use to you. It looks like for its speed and whatnot it shouldn't be too hard to make a node for.

10-11 data bits header, 8 bit data, no CRC. Doesn't look like anything harder then class 2 stuff.

I sent you a pm.

[dan king]

Are you considering posting the OBDII portion of your project in the code area? I would be interested in seeing that, along with the interface.

Rgds,

Dan