24000 ppm VSS?

[Shannen Durphey]

>From memory, 88 was right around the time that the speedometer cables
were dissappearing from the GM midsize cars.  This calibration fits an
88-89 AB body (Cutlass Cierra, Chevy Celebrity & similar) with 2.5l
and 3spd auto trans.  Quite possibly, it's from a car with a digital
dash and electronic cruise control.  It's superceded due to multiple
driveability
problems.

Shannen 

diy_efi at efi332.eng.ohio-state.edu wrote:
> 
> I've come across a PROM which appears to expect a 24000 pulse-per-mile
> VSS.  Its the ANAM1667 used in the 1227748 ECM.  This PROM configures a
> VSS interface chip to perform an extra "divide-by-6".  Other PROMs for
> this ECM set it to "divide-by-1" mode.  The ANAM PROM also has an extra
> factor of six in the VSS to vehicle speed calculation code (which gets
> the VSS signal before the hardware divide).
> 
> Could this PROM be for a reluctor type VSS?  I should have kept track of
> what type of car it came out of.
> 
> --
> Ludis Langens                               ludis (at) cruzers (dot) com
> Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/