The other day my check engine light came on. My wife took to Autozone today and jsut called. She said they told her the only code was for Manufacturer Transmission Control... What does that mean? Is that the MCU? When I purchased the Blazer, about 5 months ago it was running fine. It has 150k miles on it, and the previous owners had the tranny rebuilt 2-3 years ago. Shortly after getting it, it started acting funny at about 50 mph... after some research, and help from this forum, I narrowed it to the torque converter. I put some quick fix stuff in it, and the problem subsided.. So I've been driving it since... Now this. It has been shifting hard as crap into 2nd, but I'm not sure if this is the end of the tranny or something that can be fixed easily... Anyone got any ideas? Seen this before?

 

That just means that their code reader couldn't access that part of the PCM. The transmission codes are separate from the normal engine codes. Most likely, you'll need someone with a Tech2 or equivalent scan tool.

 

Thanks for the info! I'll try and get it in to a friend that works at a tranny shop. See what he thinks. I don't really trust his boss (the shop owner), but I do trust him so I'll wait until next Saturday most likely.

 

Have you tried changing the transmission fluid and filter? I changed the fluid and filter on my dads truck and his transmission shifts as smooth as ever. I'd do that before taking it anywhere.