GMECM Digest V1 #160

[steve ravet]

Search for drac in the diy_efi archives ...

I did and what I read leads me to believe that the DRAC is a frequency
converter that is used to drive the speedometer.  Do you have the
schematic?  If so just do what they did.  Just give the ECM the
frequency it expects, and be aware that some count pulses and some count
zero crossings.  YMMV

--steve

Nolan wrote:
> 
> Hi I'm hoping some one can give me some info.I'm building a pulse generator
> with a 555 to make aake VSS signal. I order to feed this signal to the ECM
> do I have to go thru the DRAC (its a 7749 Syclone computer) or can I feed it
> directly to the ECM?
> 
> Thanks
> 
> Nolan

-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com