DRAC for 730 to 749 conversion

[Dan Plaskett]

In changing from 730 ECM running 1991 Corvette AXCN code to 749 ECM running
SyTy code I've run into a couple of questions.

First, in the Corvette code there are two VSS inputs high and low that run
from the VSS sensor mounted on the transmission.  The Pinout diagram for the
SyTy does not use VSS inputs but instead uses a DRAC signal on pin C6.
After searching and reading the archives my conclusion is that I need to
obtain the DRAC to get the vehicle speed information into the ECM.  I am
running a mechanical speedo so I am not really concerned about the VSS
outputs that normally drive the speedo but it seems that I still need the
DRAC.  Without it the engine would have the problems associated with running
no VSS, potential for stalling, incorrect idle speed when moving, etc.  Is
my analysis correct?

Second, pin E8 in the SyTy code is labeled CAC control.  Is this a cooling
fan control?  I can't seem to find anything else on the SyTy that looks like
the cooling fan relays on pin E8 and D12 of the Corvette code.

TIA

Dan Plaskett
61 Corvette TPI w dual Paxton superchargers



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