Quote Originally Posted by kur4o View Post
I am sure pcm sends some 4000 ppm signal to ccm, along with cruise control and other modules that need to know exact speed.
That's not it. No modules connected to the CCM require the CCM to broadcast vehicle speed. The Cruise Control Module on the Y-body has a direct 4000 ppm signal input straight from the PCM, and has no connections to the CCM whatsoever.