Re: What model ECM is this ?

[Shannen Durphey <shannen@grolen.com>]

Team ZR1 wrote:
> 
> Mark, I have tried compares with ZR-1 E-proms of 91,92,94 and 95.
> 
> I think that since the ECM changed for '91 that I could be limited in what to
> compare to
> 
> I think the older ECM for the Corvette were 8 bit and it was in 94 that a 16
> bit was used for OBDII needs
> Correct ?

Specifically speaking of the ZR1, model years 1992, 1993, 1994
definitely use the same ecm.  The part number changes a couple of
times during those years.  I can find no link between the 331 in your
car and any 92 and newer part numbers.  The best check is to call a
dealership parts department and ask them to look up which part numbers
are still valid.  

If you're talking "plain" corvettes, model years 90 and 91 use one
ecm, the 92 and 93 units share a different ecm, 94 and 95 use a
different part again.

> Which processor did they use ?
> 
> John
> 
> Mark Romans wrote:
> 
> > John:  What year prom are you  comparing yours too?  If the ecm is a 90,
> > compare it to that.  I have seen differences like this when the code is
> > offset just a few bytes, when in reality those few bytes are the only
> > difference.
> > Mark