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involuntary acceleration

J.Ferreira

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Is the engine cold? The ECU sometimes keeps the idle RPMs up above 1500 while it's warming up.

Try looking up "High Idle" or "Fast Idle" and see if that seems to describe what you're experiencing.
Yeppp
If I put it in gear too early (manual) I don't even need the throttle to get going.
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I have an auto and can attest to the motor sort of jerking a bit when cold and going slow. almost feels like someone kicks the pedal repetitively. it absolutely goes away when it warms up (which doesn’t take long at all for me). andddd it absolutely comes back when it cools down again. kind of embarrassing when i drive past my neighbors. they probably think i don’t know how to drive
 

Heimkehr

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I have a manual Jeep, and when coming to a red light or stop, I leave it in neutral and the Jeep accelerates to 2000 rpm then fluctuates for a few seconds . I'm thinking tps?
Rev hang, likely for the sake of emissions.

The 2.0T's direct injection scores a win here, since by its very function there's no excess fuel that needs burned off, as it would in the Pentastar (w/the third pedal) by virtue of its port injection design.
 

mwilk012

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Rev hang, likely for the sake of emissions.

The 2.0T's direct injection scores a win here, since by its very function there's no excess fuel that needs burned off, as it would in the Pentastar (w/the third pedal) by virtue of its port injection design.
Except there are no 2.0’s mated to a manual transmission.
 

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Dvic

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2023 Jeep Wrangler 4-Door, 3.6 Automatic: Twice now, as I was coasting at about 10 MPH level driving through a campground, I experienced an involuntary acceleration as though the pedal was being intentionally pushed. It was as though some automatic control was taking over. I gained control by pushing on the brake to slow the engine down to an idle. I came to a stop and just noted that 'that was weird'. It happened twice now.

I took the vehicle to the dealer for having someone look at it. Of course, nothing was wrong and there were no error codes to reference. The technician told me that the "transmission control module" was reset. What? Okay, I am to go at it again and see if this happens again. Has anyone experienced this kind of issue? Is there any other thing I should be looking for related to involuntary acceleration? This can't be normal.
I had this happen twice with my 2021 wrangler 43000 miles and I had two rear ends coming to a stop at a red light in the past 2 months. At first I thought it was just the rain first time it happened. This last time I was braking for a while and it accelerated and ran up on the back of a motorcycle. Ticketed for failure to control speed. Taking to dealership Monday. Scared to drive it anymore.
 
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I had this happen twice with my 2021 wrangler 43000 miles and I had two rear ends coming to a stop at a red light in the past 2 months. At first I thought it was just the rain first time it happened. This last time I was braking for a while and it accelerated and ran up on the back of a motorcycle.


Was your experience when you ran up on the back of a motorcycle, with the engine being cold? Your acceleration issue may be different.

This involuntary acceleration happened again to me, with the engine being cold. By now, I have lived with knowing that when I start driving with a cold engine, the undesired acceleration is possible. It is repeatable. The engine revs as though the gas pedal is being pressed and the car moves forward if in gear. I do not like how it happens but have adopted just waiting until the engine warms up a bit longer before putting it in gear. Scary? You bet! The worst experience of this involuntary acceleration was at an RV Park, where driving very slowly is required for safety. Okay, enough. It is the new engine control on the JL, I guess. I had to adopt new habits with the JL.
 

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Yeppp
If I put it in gear too early (manual) I don't even need the throttle to get going.
Mine does this too! I thought it was weird. 2024 JLUR 6-spd.
 

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Mine does this too! I thought it was weird. 2024 JLUR 6-spd.
It's just the cold start. Every engine revs a wee bit higher in those first couple minutes.
It's completely normal. I've been able to do it in pretty much every manual I've owned.
 

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wreck99

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It's just the cold start. Every engine revs a wee bit higher in those first couple minutes.
It's completely normal. I've been able to do it in pretty much every manual I've owned.
It caught me off guard the first couple times it happened. I turn on the Jeep, drive down the road and get to the stop sign, the revs go up to 2k and the Jeep is still trying to go through the stop sign lol. Just something to be mindful of driving straight away instead of giving it a minute to warm up.
 

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Yes. I missed this element, maybe an important one. Both times this happened, the engine was cold.
That’d do it. The tend to rev a bit when cold to get temps up. I’ve never tried creeping with a cold engine but I’d bet that’s i
 

Dvic

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Was your experience when you ran up on the back of a motorcycle, with the engine being cold? Your acceleration issue may be different.

This involuntary acceleration happened again to me, with the engine being cold. By now, I have lived with knowing that when I start driving with a cold engine, the undesired acceleration is possible. It is repeatable. The engine revs as though the gas pedal is being pressed and the car moves forward if in gear. I do not like how it happens but have adopted just waiting until the engine warms up a bit longer before putting it in gear. Scary? You bet! The worst experience of this involuntary acceleration was at an RV Park, where driving very slowly is required for safety. Okay, enough. It is the new engine control on the JL, I guess. I had to adopt new habits with the JL.
I live on an island so it's not cold here. I was only on a brief trip to pick up food, car was running with the dog in the AC for awhile waiting for the food about 10 min, drove about 5 minutes to the place and was on my way home when the wreck happened at a red light undistracted and could do nothing to stop it. I moved my foot over even thinking I was fat footing both petals but I can assure I was only on the brake. I was braking for a good block with nothing happening, stepped harder and then it accelerated and literally shows how slow I was going on the neighborhood street because it came to a stop without hitting the motorcyclist in the back. Jeep was balancing perfectly on top of the back tire of the motorcycle both front wheels off the ground. I was able to back it off the motorcycle and park on the side of the street. No trouble driving it home. When it happened the first time about a month ago I just thought it was my fault and the rain plus it was a tap on a car bumper with no damage. Never took it into the shop that time. Ive never had a wreck in my entire driving history, drive slow and dont tailgate. This year 2 times rear ending someone at a stop. Noticed highway driving there were some sounds and acceleration was happening in the parking lots as well last few weeks. The motorcyclist said he heard grinding before it came up on his tire. Not skidding. Only other thing is my radio sometimes is not turning on. I have to restart the car several times and the radio works. Tomorrow I'm taking it into the shop. I've seen a ton of posts on this exact thing in other forums.
 

Steve104

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I live on an island so it's not cold here. I was only on a brief trip to pick up food, car was running with the dog in the AC for awhile waiting for the food about 10 min, drove about 5 minutes to the place and was on my way home when the wreck happened at a red light undistracted and could do nothing to stop it. I moved my foot over even thinking I was fat footing both petals but I can assure I was only on the brake. I was braking for a good block with nothing happening, stepped harder and then it accelerated and literally shows how slow I was going on the neighborhood street because it came to a stop without hitting the motorcyclist in the back. Jeep was balancing perfectly on top of the back tire of the motorcycle both front wheels off the ground. I was able to back it off the motorcycle and park on the side of the street. No trouble driving it home. When it happened the first time about a month ago I just thought it was my fault and the rain plus it was a tap on a car bumper with no damage. Never took it into the shop that time. Ive never had a wreck in my entire driving history, drive slow and dont tailgate. This year 2 times rear ending someone at a stop. Noticed highway driving there were some sounds and acceleration was happening in the parking lots as well last few weeks. The motorcyclist said he heard grinding before it came up on his tire. Not skidding. Only other thing is my radio sometimes is not turning on. I have to restart the car several times and the radio works. Tomorrow I'm taking it into the shop. I've seen a ton of posts on this exact thing in other forums.
That sounds horrible. Was the dealer able to figure out the problem? I have a less serious one, but only when the engine is cold. If I coast to a stop, the engine will rev to over 2000 until the jeep comes to almost a complete stop or until I push in on the clutch. And if I’m in second and braking to slow down, the engine will rev and try to speed up the jeep. And that has caused me to come close to rear ending the car in front of me. I’ve had manual cars all my life, and never anything like this. Has anyone ever replaced the drive-by-wire throttle body with a mechanical one?
 

wreck99

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That sounds horrible. Was the dealer able to figure out the problem? I have a less serious one, but only when the engine is cold. If I coast to a stop, the engine will rev to over 2000 until the jeep comes to almost a complete stop or until I push in on the clutch. And if I’m in second and braking to slow down, the engine will rev and try to speed up the jeep. And that has caused me to come close to rear ending the car in front of me. I’ve had manual cars all my life, and never anything like this. Has anyone ever replaced the drive-by-wire throttle body with a mechanical one?
Mine does the exact same thing. I've just tried to get into the habit of letting the Jeep idle at least a couple minutes before taking off. The first time this happened to me scared the crap outta me coasting up to a stop sign and the Jeep wanted to keep going through.
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