4l80e kicking back to 3rd then no up shift

[TonyO454]

The cruise button was stuck in accel

 

[Supercharged111]

The cruise button was stuck in accel

Right, I saw that. I'll have to try that in my truck, but I'm pretty sure that won't do anything if you haven't first set the cruise? And I don't see how that would throw a trans slippage code. Hopefully for your sake that's all it was.

 

[JavaMan]

I'm not convinced this was his problem. A component slipping sounds like a death sentence. Remember the 4L80 has an input and output speed sensor to measure this stuff.

The slip code isn't always a death sentence.
Mine was giving the slipping code multiple times. Just needed some valve body work, and it runs great, 12k miles.

Sent from my SM-G965U using Tapatalk

 

[stutaeng]

The slip code isn't always a death sentence.
Mine was giving the slipping code multiple times. Just needed some valve body work, and it runs great, 12k miles.

Sent from my SM-G965U using Tapatalk

Here's what I posted on the other thread,
"Last tranny oil change on my 4L60e with 225k the Penzzoil Shop made me sign some paper as a waiver! I just pulled that tranny at 255k, due to a common valve body issue (P1870,) that I've had since around 200k. The drain plug is pretty clean. Could probably service the valve body and will work just fine if I wanted to."

Was that your issue? Mine only did that after driving in the highway for 15 minutes and then taking off from a light. If I shut it off and restart the truck it went away... until I got in the highway again, etc. I didn't drive much highway for the last 5 years, so I drove it like that. But the code does say tranny slipping. Who knows?!