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Question About Adaptive Cruise Control on my 4xe

Dragonhawk

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My 2015 Cherokee held the brakes so I was surprised when my JL did not. From what I could find when I looked it up a few months ago it has to do with the Cherokee engaging the electric parking brake to keep them held for long periods.
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WannFly

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so a thought... the jeep starts moving, the object in front is still stopped. wont the front collision warning system kick in and ram (pun intended, i drive a 2019 RAM 1500 now lol) on the brakes?
 

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so a thought... the jeep starts moving, the object in front is still stopped. wont the front collision warning system kick in and ram (pun intended, i drive a 2019 RAM 1500 now lol) on the brakes?
Manual has a minimum FCW speed of 3 mph... and it also only holds the stop for 2 seconds.

The rear collision system on my ram drives me nuts. Before my lift, if I backed down my driveway at the wrong angle it would activate when it sensed the road and slam on the brakes. Also does it when I back in a parking spot that has an entrance behind it, it'll see a car coming in and slam the brakes on as I'm backing in.
 

WannFly

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and it also only holds the stop for 2 seconds.
thats what is weird, the RAM i drive will stop if the car ahead of me stops and stay stopped. May be FCA or whatever the new name is cant make up their mind
 

GATORB8

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thats what is weird, the RAM i drive will stop if the car ahead of me stops and stay stopped. May be FCA or whatever the new name is cant make up their mind
Reading the Ram manual got me thinking. There is no electric parking brake in the Jeep, but the Ram has one. There's probably a limit on how long the ACC is allowed to control the brakes, since the jeep can't set the parking brake, there may be concerns that a 3 minute stop in traffic could cause distractions, and restarting then could cause an accident.

From the Ram manual:
Will bring the vehicle to a complete stop while
following a target vehicle and hold the vehicle for
approximately 3 minutes in the stop position. If the
target vehicle does not start moving within 3
minutes the parking brake will be activated, and
the ACC system will be cancelled.
 

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michail

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Reading the Ram manual got me thinking. There is no electric parking brake in the Jeep, but the Ram has one. There's probably a limit on how long the ACC is allowed to control the brakes, since the jeep can't set the parking brake, there may be concerns that a 3 minute stop in traffic could cause distractions, and restarting then could cause an accident.

From the Ram manual:
Will bring the vehicle to a complete stop while
following a target vehicle and hold the vehicle for
approximately 3 minutes in the stop position. If the
target vehicle does not start moving within 3
minutes the parking brake will be activated, and
the ACC system will be cancelled.
Does the Ram have lane assist?
 

WannFly

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yes. I think @GATORB8 is spot on and that might explain why Jeep ACC behaves the way it does
My theory was there being no sensors in the steering wheel to know if your holding it.

Vehicle should be capable. Tazer has a brake hold feature. Although last I read I don't the brake hold is supported in the 4xe.

I've never driven a full stop/start system to know what it would do if your hands are off.
 

Skades 89

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Is this a new thing with the brake release? My 2014 Trailhawk has it and it stays at a stop while the ACC is engaged. When the car in front of me went I would hit the resume button and it would start moving again.
That’s how it worked on my 2018 Ford F-150.
 

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To me this is annoying, but the real issue with the ACC is how responsive the sensors are to vehicles entering/exiting your lane, and how "gently" it brakes/accelerates.

It takes FOREVER to notice when a vehicle is exiting in front of me - they'll be halfway down the ramp before the Jeep stops tracking them. Similarly, if I'm traveling at speed and another vehicle comes in front of me, also at speed, the Jeep will *slam* on the brakes until it gets the "appropriate" distance behind them, then it guns it to get back up to speed/appropriate distance.

It definitely needs some software upgrades to enhance the overall smoothness of transitions.
 

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GATORB8

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To me this is annoying, but the real issue with the ACC is how responsive the sensors are to vehicles entering/exiting your lane, and how "gently" it brakes/accelerates.

It takes FOREVER to notice when a vehicle is exiting in front of me - they'll be halfway down the ramp before the Jeep stops tracking them. Similarly, if I'm traveling at speed and another vehicle comes in front of me, also at speed, the Jeep will *slam* on the brakes until it gets the "appropriate" distance behind them, then it guns it to get back up to speed/appropriate distance.

It definitely needs some software upgrades to enhance the overall smoothness of transitions.
Both of those, and also when I change into a lane that someone just passed me in, slams on the brakes. Bad when you are moving into a gap in the left lane and it slams on the brakes in front of the next vehicle.
 

michail

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Both of those, and also when I change into a lane that someone just passed me in, slams on the brakes. Bad when you are moving into a gap in the left lane and it slams on the brakes in front of the next vehicle.
Yeah, I've about given up on it, at least in crowded conditions, which is where it would be the most useful! It brakes way too hard when all it needs is a little coasting. That and it tracks vehicles that have changed lanes in front of you.

I also had an incident overriding ACC that gave me one of the infamous highway shutdowns.
 

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I like the adaptive cruise control function on the 4xe. I accept the limitations it has and drive accordingly. It is not a fully autonomous driving experience. I still have my hands on the steering wheel, I'm still ready to accelerate or brake as required, such as I still slow down or speed up if a vehicle needs to merge from an on-ramp on the highway. I like it for long stretches on the highway where it helps me maintain the speed I want. I'm sure we all use it differently, but I like it.
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