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Old 07-23-2012, 05:13 PM   #31
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Just had something similar happen yesterday bu mine is an automatic, so I figured it was just downshifting because I had the cruise on and was going up and down hills on a highway doing about 55-60 mph. It was scary the first time. Did you have your cruise on maybe? Were you towing anything? Dont the jk's have auto hill assist just for those reasons of aiding you in slowing down while going downhill. I may be way off with that so don't bbq me to bad.

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Old 07-23-2012, 05:17 PM   #32
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Quote:
Originally Posted by kjwhite622 View Post
Just had something similar happen yesterday bu mine is an automatic, so I figured it was just downshifting because I had the cruise on and was going up and down hills on a highway doing about 55-60 mph. It was scary the first time. Did you have your cruise on maybe? Were you towing anything? Dont the jk's have auto hill assist just for those reasons of aiding you in slowing down while going downhill. I may be way off with that so don't bbq me to bad.
Hill assist does not work this way. It would not be active when traversing speeds described by the OP.

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Old 07-23-2012, 05:25 PM   #33
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Nope not towing anything and not on cruise control either. Just driving along and bam sudden decel. When it happened were you going down hill?
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Old 07-23-2012, 05:29 PM   #34
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Quote:
Originally Posted by kjwhite622 View Post
Just had something similar happen yesterday bu mine is an automatic, so I figured it was just downshifting because I had the cruise on and was going up and down hills on a highway doing about 55-60 mph. It was scary the first time. Did you have your cruise on maybe? Were you towing anything? Dont the jk's have auto hill assist just for those reasons of aiding you in slowing down while going downhill. I may be way off with that so don't bbq me to bad.
Hill decent control doesn't apply in your case. However, autos are only equipped with it. This is what it is:

Hill Descent Control (HDC) – If Equipped
HDC is only intended for low speed off-road driving.
HDC maintains vehicle speed while descending hills in
off-road driving conditions by applying the brakes when
necessary.
The symbol indicates the status of the Hill
Descent Control (HDC) feature. The lamp will
be on solid when HDC is armed. HDC can only
be armed when the transfer case is in the “4WD
LOW” position and the vehicle speed is less then 30 mph
(48 km/h). If these conditions are not met while attempting
to use the HDC feature, the HDC indicator light will
flash on/off.
When enabled, HDC senses the terrain and activates
when the vehicle is descending a hill. HDC speed may be
adjusted by the driver to suit the driving conditions. The
speed corresponds to the transmission gear selected.
Gear Approximate HDC Set
Speed
1st 1 mph (1.5 km/h)
2nd 2.5 mph (4 km/h)
3rd 4 mph (6.5 km/h)
4th 5.5 mph (9 km/h)
DRIVE 7.5 mph (12 km/h)
REVERSE 1 mph (1.5 km/h)
However, the driver can override HDC operation by
applying the brake to slow the vehicle down below the
HDC control speed. If more speed is desired during HDC
control, the accelerator pedal will increase vehicle speed
in the usual manner. When either the brake or the
accelerator is released, HDC will control the vehicle at the
original set speed.

You also have hill start assist which keeps autos and manuals from rolling in reverse, basically when you're stopped on a hill. It can be disabled if you want. It works automatically when you're on a hill and brake pressure is applied. Your manual goes into more detail.
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Old 07-23-2012, 05:50 PM   #35
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Quote:
Originally Posted by Yukonsavage
Nope not towing anything and not on cruise control either. Just driving along and bam sudden decel. When it happened were you going down hill?
Yes I was going downhill when it happened, but I do have an auto.

Thanks for clearing that up on the downhill assist, and thanks for not bbq'in me. Good to know though.
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Old 08-02-2012, 01:21 PM   #36
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Took it into the dealer Monday and of course they wont do anything cause they cant make it happen with them in it. Frustrating. I don't think its going to turn out pretty in the winter time when it happens.
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Old 08-03-2012, 02:54 PM   #37
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I'm just guessing. Could it be some kind of problem with the transfer case or linkage? If the system went to low range at 63mph it would feel like you jammed on the brakes.
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Old 08-03-2012, 03:21 PM   #38
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I have a 12 manual and have had the ESC kick in.
(weird off camber turn with a dip in the middle that is normally sandy Wasn't going fast but with wheels turned, suspension compressing and the inner wheel catching the sand it's enough to engage it)
I can tell you that even at low speed it seems violent and will surprise you if you aren't expecting it.
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Old 08-03-2012, 05:39 PM   #39
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Quote:
Originally Posted by Dale_K View Post
I'm just guessing. Could it be some kind of problem with the transfer case or linkage? If the system went to low range at 63mph it would feel like you jammed on the brakes.
transfer case is manual. if you somehow managed to grind your way into 4 low at 60mph, the engine would've blown up along with the TC.
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Old 08-04-2012, 05:35 AM   #40
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Sounds like the PCM is closing down fuel flow. That would explain the sudden decel. You shouldnt get any substantial rise in engine RPM, though. Some, maybe, on a downgrade, just from inertia. Next time, watch the tach. See if it's really increasing RPM, or if it just SOUNDS like it is. The clutch might be slipping. The fuel cut off program is used in lots of modern engines to decrese emissions and increase MPG. I never really noticed it working in my Wrangler, both my Patriots had a really aggressive cut-off. When deaccelerating, above 1500 RPM, with no throttle input, the computer would cut off fuel to the injectors. Try holding just a bit of throttle going into the downgrade, or decresing your entry speed so the engine is BELOW 2000 rpm.
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Old 08-24-2012, 01:36 PM   #41
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I have a 2012 Jeep and it's at the dealer today for the same problem. I was driving it last night around 25 mph and within a 1/4 mile, the ESC engaged 4 times. It felt like I was bogged down and the steering wheel was being jerked from both sides at various times. I LOVE Jeeps. The Dozer is my third and now frankly I am scared to drive it. My a/c also goes out for a few seconds from time to time. I could live with that I guess. I'll let you know if my dealer comes up w anything.
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Old 08-24-2012, 03:59 PM   #42
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ESC is kicking in.

Have you tried going back to the same section of road? I have a similiar issue with mine on one particuliar turn here. It's an offcamber, downhill, 90, with a dip in the middle. Mines a manual, 2011. Wife has taken the same route since new to work and during our buildup in progress, issue suddenly cropped up after a draglink flip. In the turn it'll suddenly kill the power in the turn and activate abs. Easiest way to describe it is like hitting a jakebrake. It doesn't race, but the engine gets louder as the computer shuts down the throttle, when the nanny kicks in. I thought the wife was nuts. I could do high speed turns, high speed S and 90 turns, deliberately trying to get it to kick in around a parking lot. Nothing. Sure enough I go to the turn and whammo. Wouldn't matter if I hit the turn at 35 or 65, it'd set it off. Difference would be in severity in the nanny kicking in at different speeds. Never have or had an esc issue, other then that one particular turn. Unfortunately chryslers idea of shutting off esc and mine are drastically different, as switching it off was a joke and made absolutely no difference in the turn testing.

With 99% certainty with yours, id say its esc kicking in. I do know the dash lights flash when it comes on, but unless you're looking for it, youll easily miss em.

Could just be a combination of the road and weather that set it off and you won't see it again. Like mine its only at that one turn. I've done some more changes and need to go back to see if there's a change, as she takes the fwy to work now. Id see if you can replicate again driving the same stretch to help you pinpoint it and if so, take the tech there.
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Old 08-24-2012, 04:02 PM   #43
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Quote:
Originally Posted by Blastek View Post
transfer case is manual. if you somehow managed to grind your way into 4 low at 60mph, the engine would've blown up along with the TC.
This. Transfer case and manual tranny downshifting, you can rule out.
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Old 08-24-2012, 05:02 PM   #44
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I had my ESC kick in and trouble light come on twice on a a road trip. I took it into the dealer and they said there was some flash needed to be done to the ESC.
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Old 05-13-2013, 06:15 AM   #45
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What was the outcome of this? My ESC just started to kick in while driving at Hwy speeds. It happened about 6 times today.
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Old 08-07-2014, 02:38 PM   #46
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Nothing ever came about it from the dealership. Same excuse as usual they cant make it happen again.
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Old 08-07-2014, 04:08 PM   #47
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I cannot see a manual transmission doing this. Clutch out, gears locked, no way. This must be in the ESC. Keep us posted what you find. I would get this checked pronto. That kind of change on ice will put you in the ditch.
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Old 08-07-2014, 06:20 PM   #48
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Originally Posted by highwayman View Post
ESC is kicking in.

Have you tried going back to the same section of road? I have a similiar issue with mine on one particuliar turn here. It's an offcamber, downhill, 90, with a dip in the middle. Mines a manual, 2011. Wife has taken the same route since new to work and during our buildup in progress, issue suddenly cropped up after a draglink flip. In the turn it'll suddenly kill the power in the turn and activate abs. Easiest way to describe it is like hitting a jakebrake. It doesn't race, but the engine gets louder as the computer shuts down the throttle, when the nanny kicks in. I thought the wife was nuts. I could do high speed turns, high speed S and 90 turns, deliberately trying to get it to kick in around a parking lot. Nothing. Sure enough I go to the turn and whammo. Wouldn't matter if I hit the turn at 35 or 65, it'd set it off. Difference would be in severity in the nanny kicking in at different speeds. Never have or had an esc issue, other then that one particular turn. Unfortunately chryslers idea of shutting off esc and mine are drastically different, as switching it off was a joke and made absolutely no difference in the turn testing.

With 99% certainty with yours, id say its esc kicking in. I do know the dash lights flash when it comes on, but unless you're looking for it, youll easily miss em.

Could just be a combination of the road and weather that set it off and you won't see it again. Like mine its only at that one turn. I've done some more changes and need to go back to see if there's a change, as she takes the fwy to work now. Id see if you can replicate again driving the same stretch to help you pinpoint it and if so, take the tech there.
THIS^ Googled Jeep ESC, and found the following in a safety feature video (emphasis mine):

Electronic roll mitigation (ERM): An extension of the electronic stability control (ESC). Uses input from ESC sensors to anticipate if the vehicle is at risk of entering a potential roll situation then reacts immediately, applying the brakes individually and modulating throttle position as needed to attempt avoiding a roll situation
Electronic stability control (ESC): Enhances driver control and helps maintain directional stability under all conditions. Provides the greatest benefit in critical driving situations such as turns, and is especially valuable when driving on mixed surface conditions including snow, ice or gravel. If there's a discernible difference between what the driver directs through the steering wheel and the vehicle's path, ESC applies selective braking and throttle input in order to put the vehicle back onto the driver's intended path.

As you can see, the ESC will do some strange things if it senses a possible roll over situation. Does anyone remember Ralph Nader and the old CJ5's? The modern ESC is a direct descendant of those problems from the 70's!
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Old 08-07-2014, 07:06 PM   #49
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There is such an amazing wealth of techs-pertise on this forum.

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