I am wondering about the ECM in my car, a 350TPI in a 1991 GTA.

What I am wondering about is if it sends information for mileage, I asked the guy that created winALDL and he says the 1984-1989 Corvettes(cross-fire and TPI) transmit a 5-byte datapackage from the ECM to the dash for MPG calculations.

Does my ECM send this data even though I do not have a digital dash, and what is the nature of this datapackage?

I mean is it a compilation of information from various sensors?

What I am getting at is that if that is so then even if my ECM does not send the same kind of data then atleast the information used to create said data package might be available in raw format and could then be compiled on a computer hooked up to the ALDL port to create MPG information.

 

The standard ALDL stream sends the IP fuel in bytes 49 & 50, and the accumulated distance in byte 51. From these and an injector flow constant the MPG can be calculated.

RBob.

 

thanks, now if only I knew how to program