Ok, heres the deal. I did lots of research on here and couldn't find anything exactly like my problem.

97 blazer. 4.3L, auto, 4x4. The transmission will not shift out of 1st gear usually. It will very rarely(have barely driven it since the problem started) shift into 2nd, 3rd once.

It will not shift manually either. I replaced the filter and put fluid in and checked the fluid. No codes came up on the code reader.

I inspected the wires and lines around the tranny. Nothing looked too bad.

The tranny does not grind, slip or anything in 1st, and sometimes shift. So I'm confused what my problem might be.

 

Do you have reverse?

Have you read down through the thread below to see if any of the symptoms match yours?
4L60E Information & Common Problems - Compilation

 

yes I do have reverse, forgot to mention that. No I don't think I've read that thread I'm about to though.

Well, after reading that thread I am just as confused. In the first list the symptom I saw that I had was no 2 or 3. i might have 4 but I can't get going fast enough for it to shift into 4.

If it is my shift solenoid that is messing up, wouldn't it throw a code? which one is solenoid B?

 

Sometimes yes, sometimes no. It depends on whether it is a problem with the solenoid itself or with the valve the solenoid moves.

You can have a look at the Solenoid B codes for further diagnostic steps even if you don't have these codes present:
P0756 - Shift Solenoid B Performance or Stuck Off
P0758 - Shift Solenoid B Electrical

 

Hmm, I'm still kinda confused because I can't shift the transmission manually. It just doesn't make sense to me. I don't really see this symptom anywhere in the problems others had.

I just thought of this I wonder if it has any correlation... When moving it into the garage or in the driveway, the back wheels really want to turn. I can try to creep forward just a little bit and it will try to keep going even with the brake in. I have to shift to neutral to prevent it from "taking off"

 

update: would the transmission fluid pressure switch cause this problem? mine looks like it might have a broken piece, I can post a picture.

 

Here is the list for a first gear only condition: