Overdrive shifting delays

[Ryan Carroll]

Hi guys. I’m new here and fairly new to the dodge Cummins club. I have a 2001 Dodge Ram 2500 diesel with a 47re transmission. Lately I have been having a problem with the overdrive kicking in when it is warm. For example... if I start the truck up cold and jump onto the highway the overdrive acts more normal and shifts normal at around 2200 rpm. But if I drive around town and let the truck heat up and then hit the highway,It takes longer to shift into overdrive and the engine is at 2800 -3000 rpms. I have to really get it going in order to shift. After driving on the highway for a bit and I let off the gas, it will downshift at about 50 mph and then if I give it a little gas it will shift into OD. I’m at a loss.
I have replaced the tps with a brand new one hoping this would fix the issue became I received a low voltage error once. So I replaced it and calibrated it and that didn’t fix the issue. I was thinking the ecm was getting too hot( I have had a ecm get too hot and kill the engine before. Any help would be help.

 

[Ryan Carroll]

Anyone have any ideas?

 

[DavidC]

Transmission speed sensor on the drivers side rear of the pan ?. Just a guess but it supposedly involves shifting.

 

[Ryan Carroll]

I’m not getting any codes anymore. Not after swapping out the tps/apps. But it happens when it is hot outside and the truck has running for 10 min. But not when the temp outside is cold or if I start the truck and jump on the highway.

 

[Ozymandias]

Transmission speed sensor on the drivers side rear of the pan ?. Just a guess but it supposedly involves shifting.

I second this. TSS is affecting shift points.

 

[Ryan Carroll]

Would heat affect this? I’ll snag one today and try to slap it in.

 

[DavidC]

Would heat affect this? I’ll snag one today and try to slap it in.

Yes, it is an electronic sensor

 

[Ryan Carroll]

Yes, it is an electronic sensor

Hey, I appreciate the help. Thank you.

 

[Ozymandias]

Easy to swap out, you just lose a couple drops of ATF.

 

[Ryan Carroll]

Easy to swap out, you just lose a couple drops of ATF.

Would you happen to have a part number?

 

[DavidC]

I had to break out the Magic Creeper and crawl under the truck as I didn't remember that it screwed in
Amazon product ASIN B0048YKWO8

 

[Ryan Carroll]

I had to break out the Magic Creeper and crawl under the truck as I didn't remember that it screwed in
Amazon product ASIN B0048YKWO8

You are the greatest. Thank you. I’ll give it a try. We are having a “monsoon” right now in anchorage so I may need to wait until it stops raining. I appreciate the help. I have been at a loss. Some things I have read is a ground wire is messed up and other say the Alternator Needs replaced. Along with a dozen other “hacks” dealing with the ecm/pcm.

 

[DavidC]

Don't replace an alternator, test it first
https://www.turbodieselregister.com/threads/dead-pedal.268721/#post-2626603

 

[Ryan Carroll]

I had to break out the Magic Creeper and crawl under the truck as I didn't remember that it screwed in
Amazon product ASIN B0048YKWO8

i replaced it and if anything it is a little worse than it was. I tested the alternator and it is fine. I am at a complete loss. Another Symptom is when it does finally get into overdrive if I am going 70 and let off the gas Completely to coast to 55-65 for construction zones it will downshift and as soon as I get give it a little gas it will go back into overdrive.

I don’t know if it will help but I ordered a noise isolator Amazon product ASIN B003LFPY5M

 

[DavidC]

I guess the easy cheapest way didn't work

This is about as close as the Service Manual get's that I can find

 

[DavidC]

Some more info

 

[DavidC]

 

[DavidC]

I guess the next thing I would do is disconnect the batteries and cycle (partially unplug) all of the relevant connectors, C1,C2,C3 and the plug on the passenger side of trans.. Then clean the battery terminals. May have minor corrosion in some of the pins and it doesn't cost anything but time.