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HELP !!!! Transmission Problems

1K views 4 replies 2 participants last post by  CTDFan5.9 
#1 ·
I started a new post for this because its not broke so to say anymore but it is not working right.

So here it is. It goes into limp mode after getting it up to high way speed....70 mph. Then when i come back to stop it stays in 3rd gear. To combat this problem the tranny shop has put a new governor overdrive sensor and sylinoid in. That didnt work. We dropped the line pressure a little. That didnt work. Replace the wiring on the valve body twice. That didnt work. Im thoughts on what it could be. Some one on the other thread that i had going said to re flash the computer. I havent tryed this yet, what does it do by doing that. Any other ideas would be very much helpful. Thanks guys :thumbsup

Ray
 
G
#2 ·
If the problem occurs only after hitting OD, how do you end up resetting it so the problem occurs again?

Since it seems to put the trans in a limp mode after getting to OD and 70MPH, does it do this after hitting OD and say, 60-65 MPH?

Does it do this in any gear but OD, assuming you hit highway speed?

Here is what I'm getting at. The PCM knows input RPM and output RPM. If those don't match a specific "map" of IRPM/ORPM ratios, the PCM sets a code and goes to limp home. (speaking of which, LH mode is generally 2nd gear, so "they" say) Since you've replaced a bunch of stuff, I'm wondering if the PCM still sees a difference in the I/O rpm ratio, and cut trans operation to limp home. If so, you have an internal problem that isn't electrical.
 
#3 ·
I have to shut the truck off to reset it. No it does not do it if I stay below 70mph, that is what weird about it. I would think that everytime that it goes into OD that it should do it. It seems to do it just in OD.

When you talk about the PCM stuff your speakin greek to me, but would re flashing the computer fix that?
 
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