Hesitation off the line when trans/engine is cold - anyone else?

[chois]

We picked up our 2019 Ram 1500 Hemi almost exactly a year ago.

Once the weather started cooling down I noticed that it has a pretty significant hesitation, or pause, or even a hiccup when pulling away from a dead stop when the power train is cold.
My wife drives the truck most days, so I didn't notice this right off the bat, but it is very consistent. If I start the truck in my driveway, and pull down the block to the slightly uphill stop sign, the thing will start to roll a bit when I start to pull away, then fall on its face, and eventually recover. I'm not sure if it feels like a torque converter or clutch issue in the trans, or like some goofy throttle programming going on.

If I put it in tow/haul mode it does it to a much lower extent, and once the trans was warmed up over 100 it was nearly non-existent. I initially thought it was related to cold weather when I brought it in the first time, but I'm bringing it in again today for the same issue during the dead of summer.

When I brought it in last fall they started with a power train module flash, that I think was related to the acceleration "bump" that folks were reporting last year.
When I had it in a few weeks ago the tech confirmed that it was happening, checked that the software was up to date, and told me he could not do much about it beyond recalibrating the throttle pedal and throttle body, which he did. He did mention that there is not a check valve in the torque converter for this trans, and it can drain out fluid when shut off (which I'm not totally sure I buy - this is a super common and well regarded transmission).

Anyone else experience this, and have any luck finding a culprit?
I actually got a phone call from Ram Customer Care today asking if I had issues, because they noticed it had been in several times for this issue.

Thanks all.,

 

[zlman]

I asked the same thing here awhile back, consensus was it's normal.

 

[Kicker]

What grade of fuel you using? Mine does it sometimes cold-ish. I have been using reg., I am going to bump it up to the mid range and see how it is.

 

[Jim64]

I don’t think it’s normal if it was that would drive me crazy. I’ve had my 2020 since early March and I haven’t experienced any problems when it’s cold and I have ran 87 in mine from the start.

 

[Kicker]

Also, is the AC on?

 

[ZombieSlayer]

Happens more with the ac on for me, but sometimes happens without it.

 

[popcenator]

I get this too, same conditions. It also seems very sloppy in the first couple gears when you first drive the truck after sitting for a while. I think it's in the programming, because I had the TCM software updated a month so and it shifted great for a while, but now it's back. Something with how it adapts.

Sent from my Pixel 2 XL using Tapatalk

 

[Hez]

I experience the throttle hesitation sometimes too!!!

 

[brewmastr]

My rig does this, always after cold start, sometimes worse than others. Today was pretty bad and nearly caused an accident! 2020 1500 Laramie Level 2 with 5.7 and E-Torque. 1500 miles on the odometer. Being a technician myself for another brand unless RAM has a TSB for it, it is going to be very difficult for a tech to figure this out. I may need to let the truck warm up before driving. I feel like it is a fueling issue, Gasoline is less likely to vaporize when it is cold. Even if it is adequately vaporized, some fuel condenses on the cold parts of the engine before it can be burned. The engine requires extra fuel for starting so that, in spite of vaporization and condensation problems, the engine still receives a combustible air-fuel mixture. Mix that with the fact that due to emissions standards the engine and catalytic converter need to reach operating temperature as fast as possible. A rich burn is a cold burn and a lean burn is a hot burn. The engine needs to run as lean as possible while providing proper atomization of the fuel. Its complicated, something im sure could be fixed with software. The mess is figuring it all out, a job for an engineer.

 

[Coltdefender1911]

Ok, so I'm not crazy. My 2020 does the same thing. Only while cold (even in hot weather) it seems to stumble when throttle is applied. May take it in, but as a tech myself, not a dealer tech, this may be too much effort to actually track down. At least that is what I figured they will say in a nice way when/if I do take it in. Anyone have any success with a diagnosis on this issue?

 

[TBMSport]

It may be a fueling issue and/or engine temp issue, but it is NOT a cold engine issue. I have been using only 93 octane (Sunoco & BP, so far). As a former service advisor, manager, and pre-production test test driver for multiple international brands I agree it is indeed most likely a programming issue. However, it seems that the FCA brand relies too heavily on 3rd party developers, suppliers, and/or isolated internal powertrain teams for their grab bag of cool technology. This, like too many apps on your phone, causes inevitable conflicts with one another at one time and/or the other. My gut tells me that the eTorque module is the main culprit as the start- stop, shifts and standstill acceleration are all under the advertised domain of the eTorque technology. I don't think it is "plugged in" to the conversations with the ECM and TCM, which are attempting to work around a system that intermittently works properly.

I'm curious. What is everyone's axle ratio?

 

[ZombieSlayer]

I don't have etorque and my ratio is 3.21. For me it only happens when the engine's been off for at least 6 hours.

 

[brewmastr]

It may be a fueling issue and/or engine temp issue, but it is NOT a cold engine issue. I have been using only 93 octane (Sunoco & BP, so far). As a former service advisor, manager, and pre-production test test driver for multiple international brands I agree it is indeed most likely a programming issue. However, it seems that the FCA brand relies too heavily on 3rd party developers, suppliers, and/or isolated internal powertrain teams for their grab bag of cool technology. This, like too many apps on your phone, causes inevitable conflicts with one another at one time and/or the other. My gut tells me that the eTorque module is the main culprit as the start- stop, shifts and standstill acceleration are all under the advertised domain of the eTorque technology. I don't think it is "plugged in" to the conversations with the ECM and TCM, which are attempting to work around a system that intermittently works properly.

I'm curious. What is everyone's axle ratio?

Based on your reply here, you offer no evidence it is not a cold engine fueling issue.... Have you ever experienced this problem after hot restart or hot soak restart? For me it is always on cold restart, im not talking cold ambient temp's but cold engine (coolant temp below 100 degrees)

 

[TBMSport]

Based on your reply here, you offer no evidence it is not a cold engine fueling issue.... Have you ever experienced this problem after hot restart or hot soak restart? For me it is always on cold restart, im not talking cold ambient temp's but cold engine (coolant temp below 100 degrees)

I meant to say it's not ONLY/SIMPLY a cold start engine fueling issue. I have experienced it with hot restarts. Under all circumstances for me it gets worse when it gets warmer/hotter. I am going to have them check the transmission fluid levels when I take it back for a follow up warranty repair on my windshield washer pump. From my GM 6 sp experience, I know these 5+ ratio transmissions are crazy sensitive about trans temps; which fluid volumes and resulting pressures, play a massive role in.

 

[brewmastr]

I meant to say it's not ONLY/SIMPLY a cold start engine fueling issue. I have experienced it with hot restarts. Under all circumstances for me it gets worse when it gets warmer/hotter. I am going to have them check the transmission fluid levels when I take it back for a follow up warranty repair on my windshield washer pump. From my GM 6 sp experience, I know these 5+ ratio transmissions are crazy sensitive about trans temps; which fluid volumes and resulting pressures, play a massive role in.

I would say your problem does not sound similar to the one I have or is being described in this thread. I have never experienced any throttle delay or hesitation warm. If it was a trans fluid level i would expect it to be worse cold and not warm as fluid expands with heat and the level will rise, it will be at its lowest level cold. But it is definitely something worth having them look into. If it is consistent and more frequent warm/hot it would be easier for a tech to pin point rather than the problem of it being an intermittent thing that happens once maybe twice cold and then goes away like I have experienced.

 

[TBMSport]

I would say your problem does not sound similar to the one I have or is being described in this thread. I have never experienced any throttle delay or hesitation warm. If it was a trans fluid level i would expect it to be worse cold and not warm as fluid expands with heat and the level will rise, it will be at its lowest level cold. But it is definitely something worth having them look into. If it is consistent and more frequent warm/hot it would be easier for a tech to pin point rather than the problem of it being an intermittent thing that happens once maybe twice cold and then goes away like I have experienced.

I see. That could be a different matter than yours. I saw this post-https://5thgenrams.com/community/threads/2019-ram-1500-transmission-lag-then-jumps.5344/page-2

I am inclined to think mine may be trans fluid related bc of the consistency of the problem and the fact that the start-stop function keeps the converter engaged, but obviously not the trans pump. Cold starts and any time the engine temp is less than 3/8th mark it's flawless. As soon as it gets around 3/8th it gets wonky. I'm wondering if the lack of circulation and pressure hold is resulting in draining too low for the fluid pickup (I'll have to observe what sort of inclines I'm on). Or maybe air bubbles are getting sucked in the lines which would cause the erratic and inconsistent issues once the trans is up to operating temps and relying on a consistent high pressure of fluid to do its work.

 

[Kxlexus]

My truck does this when started for the first time every day. Doesn’t matter the ambient temperature. I have a Pedal Commander too. It doesn’t do this again until it has sat for many hours.

 

[TBMSport]

I LOVE MY RAM, AGAIN!!It is with curious bittersweetness that I think I have discovered the final piece to the hanging throttle, hard 1-2, 2-1, and throttle hesitation/lag issue. Bitter, because you'd THINK the dealership service department and/or RAM CARES engineering would know this. Sweet, because, well my RAM drives like it is supposed to.

The culprit: Throttle body and accelerator pedal communication were out of synch.

There are three schools of thought on how to reset the calibrations. I choose the first one on the RAM and it had modest gains. I then tested the second procedure on the loaner Cherokee that they gave me before trying it on my truck and was impressed with the change in performance. Sometimes it may require a couple of cycles to achieve your ideal throttle response; but I would recommend getting a few hundred miles of mixed driving before doing it additional times, so as to allow the powertrain modules to readjust to the new readings. I have listed what I have found online, so attempt at your own risk.

OPTION ONE-UNPLUG BATTERY (tried and found modest improvement in shifting)
1-Unplug negative battery cable for approximately 20 min and let reset. Might be a fuse you could pull instead. Not sure which #

OPTION TWO-RESET TPS & ACCELERATOR PEDAL (did once and works great so far)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Wait until all the instrument panels idiot/cycle lights go OUT (Check Engine light may stay on)
4-Slowly press the accelerator pedal all the way to the floor and then slowly let off. I think a steady and consistent motion is best.
5a-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in synch with the throttle body's opening.
or
5b-Press Brake pedal and START BUTTON to start truck.

OPTION THREE-OIL CHANGE LIGHT RESET (didn't try as I didn't want to reset oil calculations)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Within 5 seconds Press & release the accelerator pedal 3x (three times)
4-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in sync with the throttle body's opening.

OPTION HUH?-CEL Light Reset?- I disconnected the throttle pedal as I thought the accelerator pedal could be bad (still going to get another one and test it) and it triggered a CEL that would not go away after restart
-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Wait until all the instrument panels idiot/cycle lights go OUT (Check Engine light may stay on)
4-Slowly press the accelerator pedal all the way to the floor and then HOLD IT until you hear a chime. Continue to hole until CEL blinks and then stops blinking (approximately 8-10 seconds).
5a-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. This seems to reset/turn off CEL. But can't confirm.


My conclusion, as it relates to my particular series of driveability issues is that, in addition to the other needed module programming updates (LINK>> ECM, TCM and eTorque modules TSPs), the accelerator pedal/TPS calibrations were crap from the factory and needed to be reset. After researching what the other FCA products are experiencing (Challengers, Chargers, Hellcats, and otherwise), I discovered that this throttle delay/hang up situation is just too damn random to have anything to do with any particular spec or option on our vehicle. It turns out, it is most likely in the factory final vehicle checkpoint that is to blame. Basically, at the end of the assembly line, when the vehicle's modules and such are all brought together, dyno'd, calibrated and certified good to go, certain procedures need to be done with care. One of those calibration procedures is related to the synchronizing the accelerator pedal and the drive by wire (DBW) throttle body. [Youtube Potientiometer to understand their principles] Having potentiometers allows for nearly infinite adjustability in the response of the throttle body from the accelerator pedal movement, but also allows for some serious consistently-inconsistent performance from modules downstream of the network that are dependent upon the meter's output readings. In a nutshell, whoever was likely doing the final accelerator pedal calibration on our trucks must have likely just mashed down the pedal and snap released it, providing a very skewed reading. The same thing could be happening at the dealer level when/if they do module calibration updates.

Good luck

 

[Lil'Mike]

I LOVE MY RAM AGAIN!!It is with curious bittersweetness that I think I have discovered the final piece to the hanging throttle, hard 1-2, 2-1, and throttle hesitation/lag issue. Bitter because you'd THINK the dealership service department and/or RAM CARES engineering would know this. Sweet, because, well my RAM drives like it is supposed to.

The culprit: Throttle body and accelerator pedal communication were out of synch.
View attachment 67426
There are three schools of thought on how to reset the calibrations. I choose the first one on the RAM and it had modest gains. I then tested the second procedure on the loaner Cherokee that they gave me before trying it on my truck and was impressed with the change in performance. Sometimes it may require a couple of cycles to achieve your ideal throttle response; but I would recommend getting a few hundred miles of mixed driving before doing it additional times, so as to allow the powertrain modules to readjust to the new readings. I have listed what I have found online, so attempt at your own risk.

OPTION ONE-UNPLUG BATTERY (tried and found modest improvement in shifting)
1-Unplug negative battery cable for approximately 20 min and let reset. Might be a fuse you could pull instead. Not sure which #

OPTION TWO-RESET TPS & ACCELERATOR PEDAL (did once and works great so far)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Wait until all the instrument panels idiot/cycle lights go OUT (Check Engine light may stay on)
4-Slowly press the accelerator pedal all the way to the floor and then slowly let off. I think a steady and consistent motion is best).
5a-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in synch with the throttle body's opening.
or
5b-Press Brake pedal and START BUTTON to start truck.

OPTION THREE-OIL CHANGE LIGHT RESET (didn't try as I didn't want to reset oil calculations)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Within 5 seconds Press & release the accelerator pedal 3x (three times)
4-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in synch with the throttle body's opening.


My conclusion, as it relates to my particular series of driveability issues is that, in addition to the other needed module programming updates, the accelerator pedal/TPS calibrations were crap from the factory and needed to be reset. After researching what the other FCA products are experiencing (Challengers, Chargers, Hellcats, and otherwise), I discovered that this throttle delay/hang up situation is just too damn random to have anything to do with any particular spec or option on our vehicle. It turns out, it is most likely in the factory final vehicle checkpoint that is to blame. Basically, at the end of the assembly line, when the vehicle's modules and such are all brought together, dyno'd, calibrated and certified good to go, certain procedures need to be done with care. One of those calibration procedures is related to the synchronizing the accelerator pedal and the drive by wire (DBW) throttle body. [Youtube Potientiometer to understand their principles] Having potentiometers allows for nearly infinite adjustability in the response of the throttle body from the accelerator pedal movement, but also allows for some serious consistently-inconsistent performance from modules downstream of the network that are dependent upon the meter's output readings. In a nutshell, whoever was likely doing the final accelerator pedal calibration on our trucks must have likely just mashed down the pedal and snap released it, providing a very skewed reading. The same thing could be happening at the dealer level when/if they do module calibration updates

Good luck

Thanks for the tip. I tried option 1 and 2 as you listed. I'll try anything to improve the hesitation/lag and hard up/down shifts... I hope I can Make My Ram Great Again... Well, maybe not again...

 

[Kxlexus]

I LOVE MY RAM AGAIN!!It is with curious bittersweetness that I think I have discovered the final piece to the hanging throttle, hard 1-2, 2-1, and throttle hesitation/lag issue. Bitter because you'd THINK the dealership service department and/or RAM CARES engineering would know this. Sweet, because, well my RAM drives like it is supposed to.

The culprit: Throttle body and accelerator pedal communication were out of synch.
View attachment 67426
There are three schools of thought on how to reset the calibrations. I choose the first one on the RAM and it had modest gains. I then tested the second procedure on the loaner Cherokee that they gave me before trying it on my truck and was impressed with the change in performance. Sometimes it may require a couple of cycles to achieve your ideal throttle response; but I would recommend getting a few hundred miles of mixed driving before doing it additional times, so as to allow the powertrain modules to readjust to the new readings. I have listed what I have found online, so attempt at your own risk.

OPTION ONE-UNPLUG BATTERY (tried and found modest improvement in shifting)
1-Unplug negative battery cable for approximately 20 min and let reset. Might be a fuse you could pull instead. Not sure which #

OPTION TWO-RESET TPS & ACCELERATOR PEDAL (did once and works great so far)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Wait until all the instrument panels idiot/cycle lights go OUT (Check Engine light may stay on)
4-Slowly press the accelerator pedal all the way to the floor and then slowly let off. I think a steady and consistent motion is best).
5a-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in synch with the throttle body's opening.
or
5b-Press Brake pedal and START BUTTON to start truck.

OPTION THREE-OIL CHANGE LIGHT RESET (didn't try as I didn't want to reset oil calculations)
1-Foot OFF of the brake and accelerator pedal
2-Press the START BUTTON until the RUN position is achieved but DO NOT start the vehicle. (If you do, turn off, open door and let everything reset before restarting).
3-Within 5 seconds Press & release the accelerator pedal 3x (three times)
4-Press START BUTTON again to turn everything off. (Open Door?) Start the truck as normal. That should recalibrate the pedal so that you are using its full range of motion in synch with the throttle body's opening.


My conclusion, as it relates to my particular series of driveability issues is that, in addition to the other needed module programming updates, the accelerator pedal/TPS calibrations were crap from the factory and needed to be reset. After researching what the other FCA products are experiencing (Challengers, Chargers, Hellcats, and otherwise), I discovered that this throttle delay/hang up situation is just too damn random to have anything to do with any particular spec or option on our vehicle. It turns out, it is most likely in the factory final vehicle checkpoint that is to blame. Basically, at the end of the assembly line, when the vehicle's modules and such are all brought together, dyno'd, calibrated and certified good to go, certain procedures need to be done with care. One of those calibration procedures is related to the synchronizing the accelerator pedal and the drive by wire (DBW) throttle body. [Youtube Potientiometer to understand their principles] Having potentiometers allows for nearly infinite adjustability in the response of the throttle body from the accelerator pedal movement, but also allows for some serious consistently-inconsistent performance from modules downstream of the network that are dependent upon the meter's output readings. In a nutshell, whoever was likely doing the final accelerator pedal calibration on our trucks must have likely just mashed down the pedal and snap released it, providing a very skewed reading. The same thing could be happening at the dealer level when/if they do module calibration updates

Good luck

Thanks a bunch for the information. I did the oil change version because I had changed my oil about 50 miles ago and it didn’t matter if it was reset again. It works so well that I am going to change the setting on my Pedal Commander because it is now too sensitive.