I have a '98 Blazer LS with 165k. I've read endlessly to search for a similar thread to my problem to make sure I'm not restarting a previously covered topic, but I've been unable to find advice on my particular issue, so here goes.
My tranny has been stuck in limp mode for the past two months since replacing the pwm and tcc solonoids. I've just recently discovered that if I jump in the vehicle, start it up and take right off in OD, it takes off in 1st like it should and then shifts into 2nd like it should. But, if I let it warm up at all before driving, or even after about 1 minute after taking off from cold, the tranny goes back into limp mode and wants to take off in 3rd requiring me to manually shift into 2nd to take off and subsequently shifting into 3rd, and finally OD. I have every gear but 1st, even manually shifting into 1st the tranny only shifts down to 2nd.
I was pretty much at my wits end and convinced that I needed to spend some dough on a replacement tranny, but it's obviously an electrical issue going on and I'm praying that somebody on here has or is dealing with this exact problem and can offer me any help! Thank you in advance!

 

Damn, I thought for sure I'd get some kind of a response by now!! I didn't think it'd be that unheard of with what was going on. Oy

 

I have the same problem. I hope someone can answer.

 

could be the computer, have you tried a master reset by unhooking the bat for a few hrs and putting it back on? just a idea for something to try, i had to do that on my 03 cavalier a few times.

on a dsm you jumper a wire into the plug and the cel flashes in morris code, thats how you diagnose it at least. almostalways ended up being a blown capacitor in the ecu or pcm

 

come to think of it my blazer used to do the samething when id try and us the 4wd or after i used it, if that helps any.