hi,my blazer will not shift out of first gear unless you let off the gas a little and let the rpms drop and will not shift in to overdrive also has check engine light on.need help

 

I had a similar problem and wound up having to put in a rebuilt unit. I can't remember the exact cause, but it was due to cracked parts.
My cost was $1100.00, I hope yours isn't that bad.
I suggest you see if you can get a free estimate at a tranny shop.

 

Well the other post on this subject mentioned that the check engine light was on. Also mentioned that it is a 4wd... See why having duplicate posts on the same problem are prohibitted by the rules of the forum...?

Anyway, why not go down to you local Autozone or Advanced Auto and have the codes read. Let us know what the codes are and we will go from there.