You have already changed the sensors and such at least once though, haven't you?

Clear the codes, see if it comes back..... (soon.) That code shows up on my truck on a fairly regular basis. (at least once a month.)

 

About the same only comes on when I go on long rides and yeah replaced all sensors three times. Too much money in sensors for the problem to stay on, everytime I replaced the o/d sensor it fixed the problem for a month or so then the problem came back on so I thought faulty part so put it in again same thing happened a month down the road so I replaced the o/d again didn't fix the problem so I went and replaced all other sensors and solenoids in trans and the problem fixed again, then the light came back on and the trans temp light came on and I figured to change fluid and put deeper pan so I did well fixed the problem again until I just went up north so I'm just not sure any more what it could be.

 

Put an external gauge on it, and find some way to monitor what the PCM thinks trans temp is. See if the two methods agree.

 

Okay, I have different symptoms now, after I put the deeper pan=more fluid it stopped the shift out of o/d and trans temp light on now it drives fine... Until it wants to act up, took it for 2 1/2 hour drive Friday night nothing drove back 2 1/2 hours and got off the expressway trans wouldn't down shift I was at a red light flooring it going no where. Only down shifts when I manually put it in 1st then back to drive, anyone have any ideas on what would cause these problems?

 

Failing governor pressure sensor. Don't care if it's new.

 

What are the chances of it going bad twice in a row. Both times dealer parts.

 

Not very high.

Need to see what the PCM is thinking the trans is telling it, when it won't shift. A number of things come to mind, but, you need a scanner...... one that can read live data. And preferably have more than one parameter on screen at a time....

 

Funny thing it only does it when it wants to, last time it messed up was memorial weekend, so not sure what it could be, will be going through all connections this following weekend to see if anything is corroded or any bare wires.

 

There was, I think, a Technical Service Bulletin about the harness running above the valve body (inside the trans) potentially chafing thru....... I don't remember where I read that...... but, checking the wiring carefully wouldn't be a bad plan.

Given it's intermittent nature, MONTHS apart...... that's gonna be fun to track down.

If you shut off the truck, and then start it back up, does the problem take care of itself? (remember to test that next time. )

 

Not sure what you mean by **** it off then turn it back on, when ever I shift out of drive it'll fix the problem.