VSS & 730 ECM

[peter paul fenske]

Hi Mike

Well the digital output from your speedo led unit can
be converted to a zero crossing drive for the 730 by using a
cap..

As for being out by 2 to 1 there is a 4000/2000 select in
the code but I am not sure exactly which bit must be set.

Also some apps for the 730 use a digital input from
ccms so there is a bit which selects one of several vss 
drivers.

I don't have that exact info handy

Hope some one else can find it

:peter

At 09:25 AM 9/16/98 -0400, you wrote:
>I'm putting a TPI on my 355ci 85 S-10.
>I have poured over the archives and cant find an answer to this question.
>
>How can I get a 730 ECM ( 91 F body automatic chip) to use the input from a
>2000ppm VSS (tapping into the output from the solid state VSS used by the
>cruise control).  Near as I can tell, the F body program uses a 4000ppm
>signal from two inputs ( hi & lo) rather than a 2000ppm single input.
>I read that there is a select indicator, but no specifics were given about
>which byte to change.  Which pin is used for the 2000ppm input to the ECM?
>
>Any alternatives beside getting a 4000ppm VSS  would be helpful.
>
>Thanks!
>Mike
>
> 
>
>