Hello, I'm new in the forum.

I finally joined as I give up on my Blazer 2000. It has a strange problem.

It start normally, cold or warm is the same: go to 1st, 2nd, 3rd. but if I stop in a traffic light, 3rd does not come back to 2nd neither 1st.

I checked the solenoids, replaced it but same thing. then one day I removed the 4WD fuse and the tranny happy shifts as never failed.

the drawback is the instrument cluster lost many indicators. The Blazer upshifts and downshfts great, but no gas, temperature, and many other indicators.

As soon as I put back the 4WD fuse, the downshift problem is back.

I have the shematics for the VCM, and I notice the 4WD fuse "feeds" with 12V Ignition both the Transfer Case Shift Module, and the VCM at C4 connector.

So I removed the kick panel and disconnected the Transfer Case module and plugged back the 4WD fuse, in the hope the Transfer Case could be the cause of the malfunction...

The cluster gets back but the downshift problem too. So maybe the Transfer Case Module is not the cause. Then the VCM is the bad one..?

Why if I disconnect the 4WD fuse it works fine (of course, I lost many gauges)...?

Someone had this problem before..?

I do not want to fry the engine due to lack of temperature indication, and I wuoldnt like to add an extra temperature gauge :P

There is a note: when I remove the 4WD fuse, if I restart the engine imediately, the downshift still is there. I have to remove the fuse, wait 2 minutes, then run the engine and the downshift issue is gone. Of course I have to keep the fuse removed.

Please Heeeeeeeelp!!!!!!

Blazer 2000 LS
6 Cyl, 4.3L 4WD
1GNDT13W4YKxxxxxx

 

Well,

Thank for your comments hehe

It results was a faulty ECM. I replaced and now its working like a charm.