I have been working on a 99 blazer for friend and am a little stumped right now. The problem is that it doesn't shift right. It seems like it switches from 1st and skips 2nd and goes straight to drive. It won't downshift to 2nd on its own, but you can manually shift it and it runs and shifts perfectly. He also told me when you first start it in the mornings and pull out, the speedometer doesn't work, but after it warms up the speedo works fine. Can anyone give me any ideas on what could be causing this problem..?
Any help would be greatly appreciated.

 

hmmmm, No suggestions..? Hopefully someone here will be able to give me an idea. If I find out the problem I'll be sure to post it just in case someone needs it for future reference.

 

Please do not bump a post after waiting a mere 5 hours. An emergency on your part does not give credence to breaking the rules of the forum.

Now, have you looked at the Tech Article section? Specifically the 4L60E common problems thread? There might be something in there that could help point you in the right direction.

 

How about other things that use vss.
How about the odo?

Does cruise control work while speedo doesnt?

 

Sorry about the "bump", to be 100% honest I didn't read the rules before asking, but I have read them now. I wasn't trying to seem pushy in any way, but I belong to lots of sites that posts tend to get buried and overlooked. I won't let it happen again.
I checked the area that you recommended but still wasn't able to find the problem that sounded the same. The blazer does shift through ALL gears, but when it shifts from low to 2nd it seems like it barely catches 2nd and goes straight to 3rd and won't downshift to 2nd unless you manually shift it(you can punch it to the floor at speeds as low as 20mph and it just won't downshift).
Once again I am very sorry about bumping my thread up earlier, that was entirely my fault for not reading the rules first. I would also like to thank everyone for the replies and for trying to help me out with this headache.

 

I'll help out with links:

https://blazerforum.com/forum/tech-a...e-first-30093/

https://blazerforum.com/forum/tech-a...ilation-37689/

If the shifts feel normal - except for timing - seems to me it's either VSS, TPS esp a combination of the two.. or the PCM.