jta

I had this same problem with mine. I did not use any of the fixes here, I installed an SMR Valve body kit. Problem gone, it locks up around 40mph under light acceleration. The trans feels tighter everywhere else too. I am very happy with it.

cowboycady

Well I have to say that the tin foil works. At least for now it does. This is my first CTD and I love it. One more thing my air bag light comes on and goes off after initial startup. Its pretty annoying driving down the road. Any suggestions on what to do?

RustyBoltz

So i first experienced this on a long drive home and did the above. And it orked to my surprise. My question is why does it work and although it does work this seems like just a band-aid on a different problem. I'd like to know that the only thing keeping it running right is 10 cents worth of aluminum foil around a little wire.
Thanks
RustyBoltz

Jturs

yeah this is a common problem i see, since i work at a dodge dealership and am next to a trans tech all day. this is what you need to do cause mine had the same exact problem and the aluminum foil only worked for a few days.

take off your fuel filter housing and intake horn to make room
and go down to your pcm on driver side of your block
disconnect the plug (via allen head) with and soldered in a ground to pin number 49 and 30 which are black with a tan tracer. works great no surges or problems.
make sure you have good connections and are nice and shrink wrapped up.

should work for you too. let me know how it goes.

Grider Pirate

This problem seems to be really common. I had it last year. After changing some battery cables, then the batteries, then more some other stuff..... Each time I disconnected the batteries to DO something, the problem would go away, but it always came back. What fixed MINE was to replace the connector for the alternator GROUND with a splice. This connector hides under the passenger side battery.
The problem IS caused by electrical noise. Good batteries, battery cables, and grounds seems to fix it in most of the cases I've read on DTR. Sometimes it is stubborn, and requires the foil wrapping and/or power line filter.
Cheers

Joe Diesel

I grounded the APPS housing to the negative on the battery (pics in my gallery) and I also wrapped the alternator wire in foil and covered it in split loom, its been working for me.

kammak

Whats this apps housing and where is it located.I'm gonna try all suggestions of ground cleaning and foil plus I want to ground to the apps housing..
Great posts guys I get piece of mind from this site.My lockup just started shifting in and out today, just out of the blue and I was scared but I'm sure it's something simple like you guys explained.

bangin6

http://www.suncoastconverters.com/im...d%20rewire.pdf

John Davison

I had been told all kinds of stuff. Someone told me "Throttle position sensor". My trusted trans shop said it was the burnt out 3rd brake light, said the lockup control reads that light and if it's burnt out, it gets confused. That seemed to work for a while. But the ground wire trick really did it. The ground wire off the passenger side battery going into the loom by the alternator, black with a tan tracer. I pulled it out of that loom, put new looming on it, and rerouted it away from the alternator. Has not shifted bad in 2 weeks now, and I've been fighting it for years.

dubc2323

x2 on that. I just did this this weekend and it worked for mine too

AppleTree

This problem in my 1999 4X4 Cummins Gen2 is like a ghost. I have read/watched many of the posts on this forum, Google, YouTube. Overdrive lock/unlock. My notes below are thoughts on my research, not a recommendation for you to take any action. BTW, this is a collection of thoughts and ideas from a lot of people across the internet with this type of problem with their 47R3 tranny overdrive locking and unlocking when you don't want it to.

What I'm feeling/understanding/seeing is that it is almost all related to Electromagnetic Induction/Interference (EMI), also known as Radio Frequency Interference (RFI), or simply high frequency "noise". And this noise is not getting grounded out before broadcasting into the PCM/computer.

Of course, basic maintenance is saying "Always make sure the ground wires are clean and in good contact with the body/frame/battery. I won't go into a discussion of this.

Over time I have replaced the TPS/APPS, Alternator, and transmission solenoids. Each solution lasts a few days or weeks then it starts again. Almost as if the Ghost needs a reset of disconnected batteries to sleep again... for a while.

People are saying that this EMI/RFI/Noise is coming from possibly LED headlamp bulbs. I had just put some in. I also had a new flat bed installed to replace the bed/box and it is loaded with LED lights. It isn't the lights, but the noise they generate being broadcast through all the associated wiring. Most people believe that the alternator is the biggest generator of noise because of the diodes not doing enough to clean up the noise which gets distributed to the dashboard computer (PCM?). There is also EMI generated noise when you have unshielded wires running side-by-side within a bundle, they create a magnate and send out a created current along these wires. A note on shielding I read about, is that unless you ground the shielding on each end of the wire bundle, any noise within the wire just gets rebroadcast at each end, instead of going to ground. I also read by someone in the O-Scope world that this dirty signal from the APPS, noise, is the main culprit, and not the alternator. Then there is the fuel pump and the AC Compressor. On these aging vehicles, it must be coming from several sources by now.

Many posts talk about opening the harness that passes by the alternator for a short distance and rerouting the ground cable from just past the water thermostat, up in front of the radiator, then back to the passenger-side battery. That didn't make sense to me. Here is what I did instead. I opened up the harness all the way back to the rats-nest of wires underneath the APPS. It turns out that there is a large positive (red) wire going from the alternator to the fuse box, a ground going the opposite direction from under the APPS to the passenger side battery, and five smaller wires, all in the same bundle. After researching this RFI thing as in individual topic, it seems that each of these wires, if they have noise, are like long antennas and broadcast noise to all the other wires within signal distance. I decided to isolate the five thin wires into one bundle (that are still unshielded) and the positive (red) wire into a second bundle (that is still unshielded). For the third wire, the negative (black/ground) wire, it seemed to me that a Battery ground is a Battery ground. So, I shortened it, wrapped it in tin foil, and put it into its own black flex tube and connected it to the Driver side battery ground instead of going all the way around to the passenger-side battery. So what this is all intended to do is isolate the three long-wire antennas and hopefully reduce the noise. Funny thing on this very long ground cable is that tracing it back into the rats nest under the APPS you find that it is connected to 5-small wire grounds that come from or go to unknown places. So there is no obvious reason to ground on the passenger side battery.

Lots of people swear by the noise filters installed at the PCM/computer. Some say they work for a long time, some for less time. This wasn't good enough for me so I kept googling. And, I did not want to cut into a wire connected to the computer. I ran into something in my research called a Ferrite Bead, and a Ferrite Choke. They are intended to capture the "noise" and dissipate it as heat through these little wrap-around clasps. These things only cost me $8.00 online and I got 4-sizes of five each for a total of 20-beads. The best thing is that I didn't have to cut a wire.

Today I added a few of the Ferrite Beads, and they are working, for now. One is on the, now isolated, positive cable coming from the alternator and going to the fuse box. Mainly because if it is a noise antenna getting the noise from the alternator, I want to keep noise from being pushed around the engine compartment or through the fuse box. I have another one about mid-way of the ground cable between the 5-wires under the APPS and the driver-side battery. Even though this line is now isolated from the alternator/computer side of the engine compartment. I placed one on a wire that I believe is a ground wire from the APPS going into a wire bundle toward the PCM. And, I installed one where people are installing the inline diode sold by several companies just below the PCM connector, an orange wire with a blue stripe. Which way does current run, and does the RFI noise always run in only one direction?

I have a few left over so maybe I will put these Ferrite beads on mostly ground lines heading out of the passenger-side battery, that do not directly ground out on the frame or the cab/body. Overkill? Not if it works, and for only about $8.00. If this RFI high-frequency noise, not the stuff you hear buzzing on the radio, is all over the engine compartment, I want to reduce it where I can.

Here is a practical example of a ferrite bead. If you look at the power cord of an old computer monitor or a desktop computer, you will see this little round clip-on thing around the power cord. It is probably a Ferrite bead and is intended to filter out/cancel the noise from the power source so your computer and monitor get a clean signal.

I am running a Napa Gold alternator after two others from another supplier failed. Maybe I need to go to an OEM alternator, although they don't have a lifetime warranty.

So bottom line is... This is what I did. I am not recommending you run out and do/try this. Do the research, talk to your mechanics, friends, and make the decisions on your own. Do what is right for you. But rerouting one ground cable and putting in a single diode didn't seem to be sufficiently industrial strength to slay the ghost.

mini14

bad diode in alternator can cause this. wrap the line that goes from the alternator to the battery in aluminum foil. If it stops it from doing it then you need to replace the alternator before it also fries your wait to start feature in the ecm.

turfguy

Had a number of 24 valves, & my main plow truck does this all the time. Wrapping in foil lasts a few days at best, maybe a week of occasional driving.
I've ran separate grounds from the alternator to the neg batt. terminal itself, rerouted the wire from neg. terminal to chassis ground, all that hullabaloo. I still have the issue. Will try more grounds when the weather breaks.

turfguy

I have done all that on my 99 plow truck- even ran an additional ground to the firewall, and that changed nothing. Been wrapping all my wires with foil near the back of the alternatorfor the last 4 years; it'll work for a week or two, then go back to hunting.
What has so far fixed mine for over a month is to unplug the black w/ yellow wire & route it over top of the battery as far away from the turbo as possible. Longest lasting fix to date. No hunting, no stuttering, no soft fade, NOTHING.
Hopefully that is a permanent fix for me