Lockup Torque Converter Disingaging?
 

I have an intermittent little gremlin that started showing up a while back. Occasionally I notice my engine rpm jump slightly, almost as if the tranny wants to down shift, but very quick, then it's gone. It may do it once or twice in a day, or not at all for a week or so. It showed up one day and did it about 6 times in 5 minutes, then gone again for a week.
My local tranny guy thinks the lockup torque converter is disingaging momentararily, and thinks it is an electrical issue. We looked for a tps but could not find one.
Is this a common problem on these trucks?
2001 Dodge Ram 3500 Dually. Cummins 5.9 24 valve. Stock Unaltered Truck, With 149,000 Miles on the odometer.
Any ideas as to what's going on here?

Signal is from the APPS ( Electronic throttle ) It is common, do a search on Transmission hunting. Everything from a bad ground to wrapping your alternator wires in tinfoil. On my 97 it ended up being a bad TPS.

Perhaps a 24 valve guy will jump in.

On my 99 it was a broken wire in the harness that goes to the transmission.
Sam

You can try cleaning up all your grounds also....

oN MY '99 THE DEALER FLASHED THE COMPUTER. Fixed it. That was 80,000 miles ago-

Don't forget to check for any codes.....

Thanks for the input guys. Where are these grounds located, and should I begin with battery maintenance? I'm going to get the truck in to check for codes as soon as I can get an appt. My local diesel shop pointed me to a shop that deals with problems of this type all the time.
Interesting thing happened yesterday. While driving on the highway in a heavy rain storm, my problem showed up multiple times in a 15 minute period. Most it has ever happened. Now today driving on a dry day, it only happened once. Any thoughts on this one?

You can do the key on-off trick to get any codes on a 2001. Key on-off-on-off-on ( 3 times ) leave it in the run position without starting. Should run the odometer with any codes present then say P-Done.

For the grounds there are 6 spots to clean. Each negative battery terminal (1,2). There is a wire that runs from each negative battery terminal to the body of the truck with an eye terminal (3,4). Not only did I clean the connector, I took some sandpaper and took the sheet metal to bare metal to give a better electrical connection. The most critical wire to clean is the one on the PCM (Powertrain Control Module) which sits on the firewall, on the passenger side (5,6). The PCM is what controls the lockup clutch. There is a ground wire on it that runs to the firewall. On my truck, I did not like the amount of corrosion I saw on my PCM ground wire, so I replaced it. Made a new one with soldered eye terminals to minimize corrosion. I also sanded the firewall and PCM where the ends connect.

Bad grounds can cause all sorts of funky issues, and can be some of the hardest to troubleshoot. Thankfully though, it does not take long to clean them and it is an inexpensive fix.

That's good advice jrs. As a retired elevator mechanic, I know the trouble a bad ground can cause. I went to work and cleaned up all the grounds you mentioned, and dremmeled off the body paint etc.( even dremmeled off the screw threads ). Took the truck 10 miles down the road and back. All quiet so far. Going to the range to shoot some clays tomorrow. That's about 2 hours return trip. That'll be a better test. I'll let you know how it goes. Regards George

It's been a few days now, and I've driven the truck quite a bit. Looks like my problem is gone, hopefully for good. Thanks for the great advice guys.

I have had the same type of problem on and off every other year or so. When I took it into the dealer I always told them to look at all the grounds, etc. Somehow they much have stumbled across it and it went away. Not this time. The Mt. Dora dealer has looked at all the grounds - I even printed out some of these threads on the subject and highlighted parts for them to check. They also said there was no codes for the TPS or APPS. So they were at a stand still. So I took it to the Sanford dealer and their diesel specialist drove it while connected up to something for codes and said that the TPS was shorting out. So that was almost $1,000 parts and labor. I went to pick it up and it did it 4 miles down the road - I took it back. Today the transmission specialist says torque converter is locking up. So at this point I said they need to call my husband, because he is going to explode. Any thoughts? I know from reading the threads that they are connected. This dealer says that they (TPS and T/C) were two issues I had going on at the same time. He said it isn't strange considering I have 171,000 miles on the truck.

For the last 3 months I fought a pulsing a nd surging engine. I started out by replacing my APPS with a Timbo APPS. No improvement. I finally figured out a few weeks ago that it was my T/C locking and unlocking. I spent 45 mins cleaning my ground wires and battery posts and connections VERY well. Any wires that could come off the truck got a good polish on the wire wheel on the bench grinder. Those that had to stay on the truck got a good polish from a grinding drum on the Dremel. I have not had a problem since that day. I am amazed what a difference it has made to tranny operations. I now know I have had issues for a while. The shift patterns are a bunch different now.

My whole story is well documented on a few threads on this forum.

Mine was jumping out of lock-up then back in. Just going down a flat highway and had been doing it in OD off going up a whinedy mountain road in 3rd lockup
APPS reset would be a temperary fix. Finaly bought a hew APPS(TPS) from Tim(williams tps) and that fixed it. The truck ran way beter after replacing the APPS(TPS) throutle position sensor

Again.... I'll say ground connections can and will cause shift issues and many others.