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

[Gman]

There's a path I use to leave my neighborhood where I have a stop sign and my truck is pointing up a hill. When the truck is cold, it's a little sluggish taking off and turning left. Happens every time, so I expect it.

I figure it's normal since the transmission functions so fantastically when it warms up after a couple minutes of driving.

 

[TBMSport]

So unfortunately, the from stop/idle issue returned, but I noticed several things that I felt were a bit off in the meantime. Even when already rolling and attempting to overtake slower traffic resulted in this dead zone delay before initiating a downshift, but even so, the motor didn't seem to be pulling as strong as I knew it could. I noticed the eco light/mode was coming on under all kinds of unpredictable speeds and loads (indication was some butt-o-meter vibrations). I could rapid tap & release the pedal a substantial degree of angle, multiple times, and the engine/RPM would not respond in the least. Even just in park or neutral, when jabbing the throttle, the Hemi just felt lazy. The truck absolutely refused to even slightly spin the tires from a standstill unless cold or right after a reset. And even then it would gradually stop doing so the more I drove. By the third or fourth full stop, it was back to normal. Lastly, I noticed that the up AND downshifts were erratic when it was triggered by a change in my throttle application. Conversely, if I kept a 'steady foot' throttle application (partial or floored), the transmission shifted beautifully.

After re-evaluating my notes and everything, this all led me to think that either the throttle body sensor or the accelerator pedal sensor was "off" or defective in the NO-throttle-to-SLIGHT-throttle range. So I ordered both a new accelerator pedal from my parts supplier dealer (P/N 68267286AB) and a Pedal Commander. One would be satisfying my instincts to solve the problem. The other would be admitting defeat, but at least allowing me to enjoy this truck and return some sanity to me.

I visually inspected both the factory part and replacement part for ANY kind of differences. Both had the same feel in spring tension and range of motion. So I attempted to find some online tutorial as to how to set up my multimeter and test the difference between the two, but that was a miserable fail. I finally decided to just throw it in and see what happens. Maybe it'll be just as defective, maybe it won't. *shrugging*

I did the following (based on the instructions of the Pedal Commander):

1. -Unlocked truck remotely and let truck sit for at least 5 min to let BCM/ECM go to sleep (so as not to trigger a CEL for disconnecting the accelerator pedal)
2. -Keep keys away from truck as the vehicle will sense your approach and wake up the modules.
3. -Used a 10mm and disconnected harnesss to remove the accelerator pedal
4. -Replaced factory installed accelerator pedal with new one (mind you, lay it flush towards the bottom of the magnesium bracket and then slip it upward into a slot. Ensure the part is flush and secure from swiveling. Hand tighten bolt. because if you don't the bolt will easily cross thread the magnesium and you now have a more expensive problem!!!
5. -Reconnect harness.

*drum roll please* I am THRILLED to say that the new part made a WORLD of difference. Just revving the motor in park the exhaust was gargling on throttle lift off. Time for the test drive. Without bothering to reset the throttle pedal (so as not to skew results), I took her for a spin. Literally. Tires lit up from a standstill. No hesitation and thing trying-to-catch-up surge. Just GO. NOW. Not once. Not twice. As often as I wanted them to. I did a light throttle application I went down a road with a bunch of stop signs. Each time, same thing. JOY!! Trans still upshifting ok. Downshifting fine. Did some aggressive mid turn throttle applications. Ahhhh... the sweet sound of rubber sizzling!! Did some rolling WOT from various speeds. Instant power and/or downshift. So I turned it off and let it sit a few minutes to see if it would be up to it old tricks. Nope. Still ready to burn some rubber. So I let it set and cool for an hour and made a run to Lowes. Still driving like a HEMI should. Took it to the car wash and let it idle in neutral as it pulled through the wash. Crept through the lot slowly so as not to get dripping splatter on the body. Took her easy down the street.

At each traffic light I would habitually remind myself to lean forward and gently egg the throttle, before realizing, OH YEAH, you don't have to do that anymore. I could feel the transmission relearning rapidly, but I do believe this is the ultimate FINAL piece to the hesitation problem.

Now, do I really need to keep the Pedal Commander as the problem is resolved?? I really would like to know how to set up the multimeter so others can figure out how to test their accelerator pedal and/or even a new one from the dealer. Any thoughts?

 

[Bcryan]

I’m interested if this would actually replace the need for a pedal commander for the most part.. I love the response I get from it but I’m going to try the re-calibration

 

[TBMSport]

I’m interested if this would actually replace the need for a pedal commander for the most part.. I love the response I get from it but I’m going to try the re-calibration

I finally decided to install the Pedal Commander yesterday and wow! What a difference! As much improved as the recalibrations and pedal replacement were, there is clearly a major issue with FCA pedal suppliers and/or ECM calibrations bc I have NEVER had this problem with all my years of driving and custom calibrating GM DBW vehicles.

I personally found ECO +2 or +3 to be to my liking. Consistent smooth, linear from-stop acceleration, no eTorque jerkiness upon start up, smooth upshifts at full throttle and smooth and instant downshift when needing passing power. Bonus? No more intermittent rushed gear slamming downshifts when coming to a stop. Granted, it is not full power as in race mode, but it's definitely the way ALL Rams should be every day. And I did still experience some absolute flat/dead spots (up to 2 seconds and half throttle) which has me now thinking either I need another eTorque recalibration from FCA and/or my throttle body TPS is glitching. Or it's relearning (I may have changed modes on the fly).

I strongly recommend EVERY RAM1500 owner file a xomllay with NHTSA on the matter to get FCA to offer a true and universal solution

I am intrigued by the Banks Pedal Monster. Unlike the competition, it runs off the OBD port and 12V source. But what I like most is that it monitors and logs data, has 2 level throttle mapping for 0-10 MPH and over 10 MPH PLUS, default response in reverse gear, offers a mobile phone app, touch pad, AND gauge pod. Twice the price of the comp, but Banks makes quality stuff!! Not having to switch modes to keep driveability at low speeds and still honk on it when I need it is very convenient

 

[Billy James]

I’m interested if this would actually replace the need for a pedal commander for the most part.. I love the response I get from it but I’m going to try the re-calibration

The re-calibration made a difference with mine.

 

[TBMSport]

It's a sad state of affairs when everyone at a large organization's Vehicle or Customer (Dis)Service has a "title", "authority", and "training" but no friggin' clue what they are doing. From RamCare to Svc Advisors to Techs.

I posted the following info in the "transmission downshift clunking when coming to a stop" or something similar thread, but it seems to have been tied in with my throttle hesitation issue".

I have had to do the process a few times as the hesitation and clunking would return every so often after more extended driving and heat build up.

I think I may have found our issue. review my notes and diagnose the problem based on the symptoms. I initially had a theory that the truck may have been UNDERfilled but the fact that the sensors were checking out as functioning ok and the problem was limited to only downshifts didn't add up. The frustration of the clunking, delayed downshifts, lurching, dangerous throttle hesitation, unsettling intermittent clunk the moment I start it up, engine octane pinging with any fuel, Stop-Start lurching upon restart, and even stuck throttle condition when doing a quick WOT-then-lift-pedal had me ready to drive this thing into a swamp.

The fact that the techs would rather search TSBs, test drive and screw around with diagnostic equipment and outright refused to take 5 minutes to physically confirm the fluid was infuriating. (You can YouTube how to check Ram/ZF trans fluid-basically its supposed to be level with drain plug WITH the truck sitting level, running in Park, with the fluid in a specific operating temp range) So, after letting the truck cool down from a quick around-the block drive, I used the air ride feature to raise the truck to OFF ROAD 2 and I could slide me and my creeper underneath. Upon loosening the bolt, fluid came GUSHING OUT so fast I had to shove the bolt back in immediately. Over the course of three separate inspections, I would say my trands was overfilled by a good 1/2 to 3/4 quart.

Each test drive and subsequent extended after checking and draining consistently improved the performance and reduced the issues to the point of non existent or "normal operation". Nothing triggered a low fluid code or return to its old shenanigans. It did take a few drive cycles for the issues to completely go away (aided by doing the throttle sensor reset).

So I think this may have been the simple "fix", especially after I came across this: Symptoms of excessive-transmission-fluid (Main takeaway being "when you have too much transmission fluid, the pressure builds within the transmission. This increased pressure allows air to contaminate the fluid. When mixed with air, the fluid then becomes frothy, which then increases the pressure even more.")

A fix that could have been easily determined and resolved with a friggin' dipstick or techs who know how to do more than just follow a TSB. Sadly, many are and will end up hating their truck and doing damage for tens of thousands of miles bc of the service interval due to such a simple matter. I just couldn't imagine driving this truck until its first trans service or worse, getting into an accident due to issues while waiting for FCA to do something about it.

So I suggest you guys that are having this issue to have a professional do a PHYSICAL check of the fluid levels. DON'T just go off the sensors. Sensors will only tell you if you're low, not OVER full.

I believe these transmission's are sealed with no or a very small vent for pressure build up. So too much fluid from rapidly heating/expanding fluid causes internal pressures to build up and throw off various sensor that signal other powertrain control inputs. And the only reason it improves over time is due to the fluid losing viscosity, but sadly your clutches, u joints, etc have also seriously degraded.

Hope this helps others

 

[dino0029]

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 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

Thanks, good to hear forums like this. Just #2 lets hope it works. Thanks again.

 

[Kenny4]

Well nothing has improved a I have a 2921 and it hesitates at take off as if it can't figure which gear it should be it. After stumbling at take off it smooths out at about 30mph. Brand new 100 miles on it.

 

[Pyleketerson]

On my second 5th gen and can confirm from my experience this is a thing. Sometimes I miss my 1987 F-350 crew cab 4 speed manual I sold a couple years ago. Sure didn’t feel like that truck was run by a bipolar computer. That thing was a piece of sh*t though. Always broke down. I digress.

 

[RamCares]

Well nothing has improved a I have a 2921 and it hesitates at take off as if it can't figure which gear it should be it. After stumbling at take off it smooths out at about 30mph. Brand new 100 miles on it.

Hi @Kenny4, we are sincerely sorry to hear this. Please send our team a private message with your VIN so that we may further investigate this for you. Thank you,

Kathryn
RamCares

 

[KnuckleBuster]

I noticed the hesitation the first time I drove it on the open road and was doing the break in procedure. Upon giving it brief full throttle, it hesitates before kicking in. Coming from a manual trans, this was totally noticeable and does it every time I'm heavy on the gas. I assumed it was a computer issue, but it drives me nuts and will ask the shop next time I bring it in. I was wondering if maybe a better intake would help, but not sure.

 

[Kxlexus]

Do the procedure outlined in this thread. It will help. A new intake won’t take care of this but it will sound faster

 

[‘19ramlveryeha]

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.

Same. 2019 hemi and does it lately. About 33k miles. I feel the gears aren’t shifting in time. I’m taking my truck in next Monday see what’s up.


Sent from my iPhone using Tapatalk

 

[frostymug]

It's a sad state of affairs when everyone at a large organization's Vehicle or Customer (Dis)Service has a "title", "authority", and "training" but no friggin' clue what they are doing. From RamCare to Svc Advisors to Techs.

I posted the following info in the "transmission downshift clunking when coming to a stop" or something similar thread, but it seems to have been tied in with my throttle hesitation issue".

I have had to do the process a few times as the hesitation and clunking would return every so often after more extended driving and heat build up.

I think I may have found our issue. review my notes and diagnose the problem based on the symptoms. I initially had a theory that the truck may have been UNDERfilled but the fact that the sensors were checking out as functioning ok and the problem was limited to only downshifts didn't add up. The frustration of the clunking, delayed downshifts, lurching, dangerous throttle hesitation, unsettling intermittent clunk the moment I start it up, engine octane pinging with any fuel, Stop-Start lurching upon restart, and even stuck throttle condition when doing a quick WOT-then-lift-pedal had me ready to drive this thing into a swamp.

The fact that the techs would rather search TSBs, test drive and screw around with diagnostic equipment and outright refused to take 5 minutes to physically confirm the fluid was infuriating. (You can YouTube how to check Ram/ZF trans fluid-basically its supposed to be level with drain plug WITH the truck sitting level, running in Park, with the fluid in a specific operating temp range) So, after letting the truck cool down from a quick around-the block drive, I used the air ride feature to raise the truck to OFF ROAD 2 and I could slide me and my creeper underneath. Upon loosening the bolt, fluid came GUSHING OUT so fast I had to shove the bolt back in immediately. Over the course of three separate inspections, I would say my trands was overfilled by a good 1/2 to 3/4 quart.

Each test drive and subsequent extended after checking and draining consistently improved the performance and reduced the issues to the point of non existent or "normal operation". Nothing triggered a low fluid code or return to its old shenanigans. It did take a few drive cycles for the issues to completely go away (aided by doing the throttle sensor reset).

So I think this may have been the simple "fix", especially after I came across this: Symptoms of excessive-transmission-fluid (Main takeaway being "when you have too much transmission fluid, the pressure builds within the transmission. This increased pressure allows air to contaminate the fluid. When mixed with air, the fluid then becomes frothy, which then increases the pressure even more.")

A fix that could have been easily determined and resolved with a friggin' dipstick or techs who know how to do more than just follow a TSB. Sadly, many are and will end up hating their truck and doing damage for tens of thousands of miles bc of the service interval due to such a simple matter. I just couldn't imagine driving this truck until its first trans service or worse, getting into an accident due to issues while waiting for FCA to do something about it.

So I suggest you guys that are having this issue to have a professional do a PHYSICAL check of the fluid levels. DON'T just go off the sensors. Sensors will only tell you if you're low, not OVER full.

I believe these transmission's are sealed with no or a very small vent for pressure build up. So too much fluid from rapidly heating/expanding fluid causes internal pressures to build up and throw off various sensor that signal other powertrain control inputs. And the only reason it improves over time is due to the fluid losing viscosity, but sadly your clutches, u joints, etc have also seriously degraded.

Hope this helps others

Is the a YouTube video you can link to that shows how to drain the transmission? I haven’t been able to find one for the DT.

 

[frostymug]

It's a sad state of affairs when everyone at a large organization's Vehicle or Customer (Dis)Service has a "title", "authority", and "training" but no friggin' clue what they are doing. From RamCare to Svc Advisors to Techs.

I posted the following info in the "transmission downshift clunking when coming to a stop" or something similar thread, but it seems to have been tied in with my throttle hesitation issue".

I have had to do the process a few times as the hesitation and clunking would return every so often after more extended driving and heat build up.

I think I may have found our issue. review my notes and diagnose the problem based on the symptoms. I initially had a theory that the truck may have been UNDERfilled but the fact that the sensors were checking out as functioning ok and the problem was limited to only downshifts didn't add up. The frustration of the clunking, delayed downshifts, lurching, dangerous throttle hesitation, unsettling intermittent clunk the moment I start it up, engine octane pinging with any fuel, Stop-Start lurching upon restart, and even stuck throttle condition when doing a quick WOT-then-lift-pedal had me ready to drive this thing into a swamp.

The fact that the techs would rather search TSBs, test drive and screw around with diagnostic equipment and outright refused to take 5 minutes to physically confirm the fluid was infuriating. (You can YouTube how to check Ram/ZF trans fluid-basically its supposed to be level with drain plug WITH the truck sitting level, running in Park, with the fluid in a specific operating temp range) So, after letting the truck cool down from a quick around-the block drive, I used the air ride feature to raise the truck to OFF ROAD 2 and I could slide me and my creeper underneath. Upon loosening the bolt, fluid came GUSHING OUT so fast I had to shove the bolt back in immediately. Over the course of three separate inspections, I would say my trands was overfilled by a good 1/2 to 3/4 quart.

Each test drive and subsequent extended after checking and draining consistently improved the performance and reduced the issues to the point of non existent or "normal operation". Nothing triggered a low fluid code or return to its old shenanigans. It did take a few drive cycles for the issues to completely go away (aided by doing the throttle sensor reset).

So I think this may have been the simple "fix", especially after I came across this: Symptoms of excessive-transmission-fluid (Main takeaway being "when you have too much transmission fluid, the pressure builds within the transmission. This increased pressure allows air to contaminate the fluid. When mixed with air, the fluid then becomes frothy, which then increases the pressure even more.")

A fix that could have been easily determined and resolved with a friggin' dipstick or techs who know how to do more than just follow a TSB. Sadly, many are and will end up hating their truck and doing damage for tens of thousands of miles bc of the service interval due to such a simple matter. I just couldn't imagine driving this truck until its first trans service or worse, getting into an accident due to issues while waiting for FCA to do something about it.

So I suggest you guys that are having this issue to have a professional do a PHYSICAL check of the fluid levels. DON'T just go off the sensors. Sensors will only tell you if you're low, not OVER full.

I believe these transmission's are sealed with no or a very small vent for pressure build up. So too much fluid from rapidly heating/expanding fluid causes internal pressures to build up and throw off various sensor that signal other powertrain control inputs. And the only reason it improves over time is due to the fluid losing viscosity, but sadly your clutches, u joints, etc have also seriously degraded.

Hope this helps others

Hey, I can't thank you enough for your post! It was more helpful than Ram Cares and the dealer I took my truck to. I have a 2021 1500 Limited and was having so many transmission quirks--from sluggishness, delayed upshifts, hard downshifting, and others. I took it to a dealer who drove it and said everything was "as designed". I was so frustrated by that, so before picking it up, I asked the service manager if he would flash the TCM and/or do a quick learn, and check the fluid. He completely refused and said he would not do any of those things since he thought the transmission was fine. I mentioned to him that I saw some posts that the ATF was over filled from the factory and he said "there's no evidence of that. If it was over filled, there would be some leaking." So DAMN frustrating.

Anyway, I decided to test it out myself by parking completely level and opening the plug when the transmission fluid was around 90F. Engine was off, but as you stated, the fluid came out quickly. So much so that about 5 - 7 ounces gushed onto the ground, so I quickly put the bolt back on, grabbed a container and came back to do it again. See attached picture for how much came out.

I then went out for a drive and magically the transmission is behaving so much better. So I drove it around for a while, came back home, and let it cool down again to around 95F and opened the bolt again. More ATF came out. Thankfully there's some good YouTube videos explaining how to ensure you have just enough ATF in the ZF transmissions.

I've am now happy to say that the transmission is almost back to normal. There are some very minor quirks that weren't there in the first 3000 miles of ownership. I can only imagine that there is likely some damage from driving over 5000 miles with the transmission overfilled, but I can only imagine how much worse it would be had I never found your post and would have kept driving it with too much fluid.

Total over fill amount looks to be around 1 quart. See pics attached. And that doesn't count the ounces that came out before I put this container underneath to catch the rest.

You would think that in this day and age of high-tech manufacturing, there would be a gun used at the factory that only dispenses the exact right amount for the specific transmission.

 

[Lil'Mike]

I can confirm this as well! I dumped about half a quart of extra trans fluid today, and plugged it back up. The truck seems to roll much smoother and I haven’t experienced the bump or clunk when shifting in my last few test drives. I might try to remove more but I got nervous when it was coming out like a guyser. Haha

 

[frostymug]

I can confirm this as well! I dumped about half a quart of extra trans fluid today, and plugged it back up. The truck seems to roll much smoother and I haven’t experienced the bump or clunk when shifting in my last few test drives. I might try to remove more but I got nervous when it was coming out like a guyser. Haha

Awesome! As long as your truck is level when you're doing it and your ATF is around 85 - 100 degrees, let it drain until there's just a trickle coming out. Let us know how it goes!

 

[Lil'Mike]

Thanks! The truck was level and the transmission temp was 95 degrees according to the dash. I will check back in after a few more days of testing.

 

[theblet]

Interesting thread. This is my first ram and first 8 speed. So not sure if it’s working properly or not. Mine seems to shift quite quickly at part throttle to get to 8th gear. Should I try the pedal reset to see if it makes a difference?

 

[Cherche]

When doing the level test - the engine is running in park or turned off?
THX
Jochen