Engine downshifts unnecessarily when going downhill

[RBAT]

2017 Laramie CC, 5.7 w/3.21 gears and has Tow/Haul. Since I bought the truck I have had a problem with the truck downshifting, often twice when going downhill with my foot off of the accelerator. This happens with or without CC engaged. The first downshift will raise the RPMs by just a few hundred but if it gears down again it will rev the engine up to about 3k. I have asked about this when I had the truck in for service but never got a helpful answer until my last visit.

While talking to the service manager about this problem he asked whether I had Tow/Haul engaged. I have never used it and in fact I had to look for the button to turn it on. Pressing that button after starting the truck and then turning it back off before driving off confirmed that it was off. But I noticed on the trip home that the problem did not occur. On the right track but not the end of the problem. If I turn the truck off and then crank up and drive away I have to repeat this process every time. If I forget and the truck downshifts on a downhill I can just reach over and turn Tow/Haul on and off and the truck returns to normal.

Is this normal operation for the truck equipped this way? Is there any way to prevent having to do this every time I get in the truck? Thanks for any help.

 

[crash68]

Keep in mind the torque converter stays locked up on these transmissions which is why you notice the downshifting when you foot is not pressing the throttle going downhill. When the cruise control is set the transmission will downshift in an attempt to control the vehicle speed close to the set speed.
What's the concern aby the engine reving to 3K rpms? The torque peak for the engine is 4K and the redline is over 5K so it's not hurting the engine in any way.

 

[RBAT]

It just seems to me that this would cause considerable internal wear on the engine as opposed to just coasting downhill. Often it is not even picking up enough speed to need to apply the brakes. So this is another case of "It's not a defect, it's a feature"? Kind of like when I backed out of the garage dragging a cardboard box that had blown under the truck. I heard the noise and continued backing out slowly and opened the door slightly to pinpoint the source of the noise. Almost got tossed out on my butt into the driveway when it "auto parked". Damn engineers.

Anyway, thanks for the reply and letting me know that this is normal.

 

[ramffml]

It's a feature (literaly). Ford's do it too, not sure about GM. Helps slow you down and saves the brakes, I love it to be honest.

 

[zogg]

It's a feature (literaly). Ford's do it too, not sure about GM. Helps slow you down and saves the brakes, I love it to be honest.

Totally correct. It’s to prevent runaway going down hill.

 

[jvbuttex]

yes my 1500 did the same thing going down the steeps

 

[John Jensen]

It's a great feature, don't fret over it, enjoy it

 

[62Blazer]

It just seems to me that this would cause considerable internal wear on the engine as opposed to just coasting downhill. Often it is not even picking up enough speed to need to apply the brakes. So this is another case of "It's not a defect, it's a feature"? Kind of like when I backed out of the garage dragging a cardboard box that had blown under the truck. I heard the noise and continued backing out slowly and opened the door slightly to pinpoint the source of the noise. Almost got tossed out on my butt into the driveway when it "auto parked". Damn engineers.

Anyway, thanks for the reply and letting me know that this is normal.

It's not causing any significant wear on the engine. Literally just spinning with very little load on it, and 3,000 rpm is only about half of the redline.

 

[RBAT]

Thanks for all the replies. I just wanted to be sure that all is well with the Ram. My other truck is a 97 Dakota 318 auto and it doesn't do any tricks. Have to get used to the new toys I guess.