I own a 1999 Dodge 3/4 ton with 5.9 Cummins and 47RE auto tranny. In 2003 I went through this issue and fixed it by moving a ground wire away from my alternator and running the PCM ground to my other battery. The transmission shifted beautifully and the problem did not come back
Every three years, the shifting problem would come back and I'd have the local dodge dealer reload the PCM program and the problem would disappear. Recently, my shifting problem came back with a vengeance. I took it to the dodge dealership, they checked for updates and cleared a TCP DTC code, said it could cause a shift problem but did not change it out. Also last Oct 2009 I had an issue where the transmission would not shift out of 1st gear which was repaired by replacing the Output Speed Sensor due to a Code P0720 read out. That fixed that shifting issue.
NOW, it's still shifting randomly whether I have the OD button depressed or not. I spent 2 hours checking this forum for shifting problems and came up with a list of things to check. First I checked for codes and got NOTHING!
I plan to check the PCM connectors and ground terminals. Can anyone think of anything else I should check? Is it time to replace the PCM? Thanks in advance.

 

governor position sensor and transducer inside the trans pan not that expensive have been a constant problem for years,

 

here is a thread, with lots of suggested repairs

http://www.cumminsforum.com/forum/98...up-thread.html

 

Governor pressure solenoid is high on list of shift issues. Generally the transducer is replaced as prudent at same time. Has a good tranny service been done lately?? Look at KD band adjustment, amount of trash in fluid, ect.
On a sidebar: Considerable review on T.C. unlock has been done on effect of poor grounds.

 

Good news! I cleaned all six ground terminals and blew out the three connectors to the PCM with canned air. Took it out for a test run and my truck shifts beautifully! I may replace the ground wire near the alternator with shielded #10 wire as a precaution. I have it tie-wrapped away from the alternator but it is definitely a contributor to this issue. Thanks for your support and suggestions.

 

Why are these trucks PCM so sensitive to grounding? I clean my grounds about every 6 months and this keeps the problem at bay.

 

Apparently the lock/unlock signal is only a volt or so and subject to any noise coming from the grounding system in our trucks. It just so happens that one of the main ground wires (# 10 wire) coming from the passenger side battery going to the engine block passes directly over the alternator causing electrical static or noise to be induced into the ground wire. Shield or reroute that ground wire helps a lot.

 

Would plain aluminum foil work as shielding?

 

Yes.... many have used it successfully.

RJ

 

I was having similar issues and would clean battery post and it would resolve for awhile. My batteries were 9 yrs. old, original from factory. Got the good out of them but they were getting weak. After putting in new bats, it's just amazing how much better the trans shifts.

 

Thanks EowJ, I wrap some good old "Reynolds" wrap on that ground wire.

 

With everything people discussed on the forum I was sure I had major problems with my 2000 3500 diesel but it turned out to be a speed sensor on the transfer case. It cost me about $180 for parts and labor. My local mechanic was able to find the issue in under an hour.

 

I have a 99 Dodge ram 3500 auto, I've just started having tranny issues. When I put it in drive it has a hesitation, then once it's going it's like you put it n neutral. Then after a minute or two it kicks in and goes, but not for to long. Reverse is the same, I've checked the fluid, any suggestions greatly appreciated

 

So I am in need of help with my 99 dodge ram 2500 24v Cummins. So I thought my trans went. But now I'm not sure. It moves when of is off but seems to still slip here and there but when in drive regularly it doesn't work at all as soon as you torn the OD off it goes back to working. Can anyone help me figure this out.
ps it has an edge juice tuner in the truck that doesn't actually work the tunes. Can this be an issue to the trans? Any advice tips whatever I can do to start looking into fixing it.
Thanks.

 

Transmission was slipping between 3rd and overdrive, this happened after the truck set all winter. It worked fine before so it seemed like an electrical issue. I cleaned the passenger side negative battery terminal and wrapped aluminum foil (tripled) around the wires running over the top of the alternator. Instantly the trans stopped slipping and 500 miles later it's working like new. I didn't think there was a chance in hell this would work when I tried it. Thanks everybody for posting how to do the repair.