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Intermittent power reduction, RPM hang when turning/going uphill

I’m going to try the manual shifting this week to and from work.

I’ve reset the computer twice already. I think it helped for a while and then it started doing it again.

The strangest thing was replacing my loose gas cap with a new one. For about 4 days straight it drove like new, then it started doing it again. I thought I had actually fixed the problem with a 6 dollar gas cap…

  1. Check the transmission fluid level and quality. Use ONLY the recommended fluid to top off or replace.
  2. Have you tried manually shifting the transmission?
  3. Are you using the proper engine oil? The MDS system uses engine oil to move the actuators. You must use the proper oil. I know you’ve said you disabled the MDS but this may still be a factor. The droning in the exhaust is a clue that it might still be active. MDS causes aftermarket, low restriction exhaust systems to sound terrible.

Hook a $5.00 vacuum gauge to the engine and take it for a ride, you’ll know in a minute if you have a restricted exhaust.

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I’d wait for the problem to occur and then, without changing gas pedal position, manually downshift. If it wakes up and runs normally afterward, you know something more about where the problem lies.

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I’m kind of ashamed to admit this but I didn’t know I could use auto stick while already moving.

It happened today and when I activated manual shifting it was accelerating in 4th gear. After I dropped into 3rd it started going like normal.

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Try recalibrating the gas pedal:

  1. Turn the key to on, but don’t start the engine.
  2. Wait for all the lights to go out (seatbelt & check engine will not go out)
  3. Slowly and steadily push the gas pedal to the floor and hold it for 3-5 seconds, then slowly let it back up.
  4. Turn the key to off and remove.
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Sounds like it’s factory programming that is the issue. An aftermarket handheld tuner might be a good option. I’ve never used one myself.

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I’ll give that a try tonight. Thanks for all the help you guys have given me. At least now I know what’s going on. I still don’t understand why it gets so much worse the longer I drive it.

I’m taking a long drive this weekend so I’ll definitely pay more attention to the gears when it happens.

Another question, maybe I missed it above, has the trans fluid been changed since you owned it? The prior owner put 6 years of use on it right? Who knows if they ever changed it. My bet is on sticking shift solenoid but start with easy stuff.

Did the transmission tech experience the problem when he proclaimed trans was shifting ok? Or just drive it cold and not have problem happen?

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The gas pedal calibration didn’t seem to change anything.

The fluid hasn’t been changed since I’ve owned it, but I’ve checked it and it looks pretty new. After this thread I’m adding it to my to-do list. I really didn’t believe it was the transmission. I wanted to do the transfer case fluid before winter hit anyway.

The “tech” (old nuts and bolts mechanic) said he thought it was becoming stuck in ECO mode (MDS). But now we know its getting stuck in 4th gear. So that’s what I’m going to pursue. I’ll start with the trans service. I think it has two filters?

Where is the shift solenoid and is there anything else I can replace while I’m in there?

The computer looks at gas pedal position to determine if it should leave mds mode. So the cal was to eliminate pedal reading as cause. You said this started after you bought it. Any chance it was at a dealer for service just before this problem started? Thinking a software update adversely changed mds performance…

If the computer is exiting mds properly, the trans may not be responding. The shift solenoid(s) could be sticking. If the fluid is 8 years old, it is overdue. It can lose performance without appearing bad. So it should be changed. Unfortunately, the shift solenoids are inside the trans. There are additives that may help clean them, it couldn’t hurt to add one after fluid change…

I don’t really know the history of the truck. All I know is it was sold in Canada originally, and the last owner had 4 RAMs and traded this one in for a newer model. I read the Carfax before I bought it but that was a while ago.

It wasn’t in for dealer service since I’ve owned it. Most of the servicing has been done by me. I’ve had two things professionally done. The exhaust and the Bilstein shocks. They cleaned the throttle body when they did the shocks on their own, since I mentioned the issues I’ve been having. It actually started acting up around the same time I had the exhaust done. July/August of last year. The shocks were done this year in March. I don’t think either shop had the tools for a computer update.

I’ll start with the fluid/filter change and go from there.