24000 ppm VSS?

[AL8001 at aol.com]

In a message dated 99-01-17 00:06:34 EST, ludis at cruzers.com writes:

>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.

This could be a prom for somthing equiped with anti lock brakes.   Some of the
Chevy trucks with rear wheel only anti lock, use the speedo sensor to feed the
anti lock and the ECM / speedo.  ( Instead of a seperate sensor located on the
rear axel houseing.)

Harold