128K vs 256K Proms in one ecm

[Roger Heflin]

On Thu, 7 Jan 1999, Bruce Plecan wrote:

> Could some one splan to me why if the 739+749 use the same
> PCB, why the 730 will not see a 128K prom, and a 749 sees 
> either. 
> 730 using AUJP  749 using syclone campaign chip 
>   On a 730 (92 Camaro), there is a 4th gear switch, that the ecm
> "uses", anyone know for what?,  timing, fuel, TCC all seem the same
> wiether it's on or off.
>   There is a difference in TCC pinouts from 749 to 730.
> The 730 basically leaves the EGR on all the time and flickers it once
> in a while to test, it.  749 seems to not even flicker it, strange.
> 
> On the syclone idle if it's below 550 the IAC retracts, that's fine,
> but as it exceeds 575 goin to a desired 600 the 600 jumps to 1250
> anyone played with this??  Seems like would be lousy idling.
> Bruce
> 
> 
The 93's seem to have switches for all gears, but there is some code
to dectect a downshift from 4th (basically if you aren't in 4th now
and your where last time then).   I appears to time the 4-3,4-2
downshift, and there is a parameter in the 93 prom that lists how long
it takes (0x05 passes).   It seems to prevent part throttle locking in
the 93's while a downshift is in progress.  I don't yet know what else
it is used for.  It also looks to be used for some other TCC type
things.  In the 92's is the TCC computer controlled yet?

			Roge