at least I can't find one. please point me in the right direction...

it seems like this is a fairly common problem. I can't believe we don't have a specific write up on how to fix this issue.

96 Blazer 4x4x4 Auto

Problem: Speedometer is not working, Transmission will not shift, and ABS light comes on. As it warms up (sometimes 1 mile, sometimes 20) suddenly the Speedo will start working, the tranny will shift, and the ABS light goes off.

It has gotten worse and worse to the point where it won't shift at all (also no speedo and ABS light is always on). This has happened to many many many blazers and I can't find a single fix, just lots of "maybe it's this" or "maybe it's that". Is there a definitive solution to this very specific problem?

Any help is very much appreciated!

 

I answered it, here.
https://blazerforum.com/forum/2nd-ge...roblems-69994/

Your pcm is not seeing vss. The vss sensor is on the rear tailshaft. 2 wires in the plug. There may be more than one on your tailshaft. Also I dont have 96 wiring drawings or I would tell you what the pcm connection is.

Remove the connector{s}, clean them up, grease with dielectric and make sure pins are good. Then check for frayed broken wiring along the path to the engine room.

If that still doesnt do it, buy 1 new one.
Worst case: PCM bad.

 

I agree, spot on perfect! Intermittent/poor connection somewhere. This is the cause of all of your symptoms.