I have a 1994 Dodge 2500 Ram w/ Cummins Turbo Diesel, auto transmission. It's been cold the last several days, and the transmission constantly shifts up and down, even when it's not in overdrive. It has approximetly 65,000 miles and the transmission was serviced at 50,000. I seem to think a sensor is bad or something. Can anyone help.

Thanks, Yodey44

 

let me guess...ur tranny shifts in and out of lockup...its the TPS sensor...on ur fuel pump drivers side is a lil plastic box thingy..that needs to be adjusted or worst case replaced

 

Man, has this subject not been beat to death? Do a search, I bet a paycheck you find answers...

 

I've read that there is a cleaning procedure to bring back to life , if you do a search there should be the info to do it. welcome to the dog owner training center.

 

You guys need to read the question before you answer, go back up and read his question again. His problem occurs even when NOT in o/d , so lets forget the TPS for a second here. My truck has the same tranny (47rh) and it does something similar/the same when it is below freezing. It appears to try and shift into third , but for some reason the shift doesn't happen. so i am left with a truck that feels like it is in N , if i manually pull it down into second , then it shifts into second and i cruise away like a herd of turtles. I do not know why the tranny does this, but My friend (apoc on the forum) has a 93 with a built up tranny, and he told me it does the same thing when it is cold.

As far as it shifting in and out of o/d , you can clean/test the tps to see if it is working correctly. I lost o/d a few weeks ago , and it turned out to be my TPS , you can replace them for over 200$ (so i am told) or clean yours in an effort to salvage it. I took mine off , and drilled a hole approx .75" in from the edge on the back side (1/16 hole) and squirted electonics cleaner in , shook it up , and dumped it out , i repeated this a few times , and it worked. You can also test/adjust the voltage on the TPS, just follow the directions listed here:

https://www.dieseltruckresource.com/...n&onlynewfaq=1

Instead of adjusting it with a wrench as they say to do, you can knock out the metal reinforced holes , and make them into an oblong shape with a small file , and just pysically turn the TPS on it's mount until you see the correct voltage.

 

Hey I took the TPS off and squirted it with a cleaner type lubricant, put it back on and it's working. I think there may have been some moisture in it. Thanks everyone for your suggestions.