No overdrive sometimes????
 

I'm starting to have a problem with my transmission in my 97 Blazer 4x4. Yesterday I was headed home from a 1500 mile trip. About half way home it wouldn't go into overdrive. then it would sometimes. I stopped it & restarted it a couple of times it would work for awhile then not. Sometimes I noticed if I had to slow down or stop that it would sometimes BANG one/two shift. After a few hundred miles of acting up it threw a code. The last time I had a code, I had it checked it was something like torque converter trying to lock up or something like that. The shop made reference to a switch or something. I say that because it was over a year ago & I can't remember yesterday.
Any ideas?? I was thinking it is electrical like a switch or module. Fluid if FULL & clean. I have a B&M SuperCooler on it.
Thanks in advance.

I guess I'll have to run the question by a transmission shop in the morning & see if they can shed any light on this issue. I drove it a 100+ miles today & it worked flawless.

Took it to a transmission shop today & described what it was doing as I did here & they told me it was the most common problem with 93-04 Blazers. They even knew what code # when I told them as I did here. So it will be fixed Wednesday. Thanks