Adaptive Cruise Control / Brake lights

DocTwinkie

Well-Known Member
First Name
George
Joined
Aug 19, 2018
Messages
482
Reaction score
570
Location
Ohio
Vehicle(s)
2020 JLUR 3.6m, 2019 Acura RDX Adv.
Occupation
Doc... Duh.
I have ACC and a manual. So there’s no engine braking. It absolutely uses the brakes at least on the manual. If I have it in 6th going down a big hill it’s pretty easy to know the brakes are being applied since cancelling the ACC I’ll start flying away down the hill. ACC absolutely uses your brakes.
Advertisement

 

TimmH

Well-Known Member
First Name
Timm
Joined
Sep 18, 2018
Messages
619
Reaction score
682
Location
Florida
Vehicle(s)
2018 JL Wrangler Sahara 3.6 Auto
Vehicle Showcase
1
Never said the Jeep was self driving, nor do I expect it to be s


I think you missed the point of the question. I've had other vehicles with ACC and the brake lights illuminate when the vehicle is slowed by the system. This one does not. I never said this was a self driving Tesla nor do I expect it to act like one so I'm not sure where you are going with your comment.
I would hope just slowing would not trigger brake lights, I want to ram people off the road who's brake lights are on and off constantly, which I always assumed was the driver riding one foot on the brake. That's worse than no brake lights at all.
 

bravelion

Well-Known Member
First Name
Steve
Joined
Jan 4, 2020
Messages
75
Reaction score
36
Location
Austin, TX
Vehicle(s)
2020 JLUR
Occupation
Real Estate Investor
I have ACC and a manual. So there’s no engine braking. It absolutely uses the brakes at least on the manual. If I have it in 6th going down a big hill it’s pretty easy to know the brakes are being applied since cancelling the ACC I’ll start flying away down the hill. ACC absolutely uses your brakes.
What you're saying may be true for manual transmission models, but not for automatics. My 2016 absolutlely does NOT use brakes for normal highway spped adjustments. It simply reduces accelerator, same as would happen if one lifted their foot from the pedal.
 

cjaama

Well-Known Member
Joined
Sep 24, 2018
Messages
397
Reaction score
318
Location
Albany, NY
Vehicle(s)
2019 JLUR
Except nobody in this thread (at least from what I recall) was stating that the brake lights don't come on when the brakes are applied. The OP's question was whether brake lights come on when other, non-brake, methods are being used to slow the car (consensus was they don't, which is how pretty much all other vehicles that don't have ACC systems work as well). So I'm not sure what your point is.
If your power of recollection isn’t accurate, don’t rely on it.
The slowing down makes sense since I am assuming ACC will be braking with the engine. There are time when it definitely feels like the brakes are being applied (especially when coming to a full stop) and my wife driving behind me said the lights never came on once. The only time they did is when I physically pressed the brake pedal down.
 

unsavory

Well-Known Member
First Name
Jimmy
Joined
Sep 17, 2018
Messages
260
Reaction score
202
Location
California
Vehicle(s)
2019 JLUR
What you're saying may be true for manual transmission models, but not for automatics. My 2016 absolutlely does NOT use brakes for normal highway spped adjustments. It simply reduces accelerator, same as would happen if one lifted their foot from the pedal.
You guys obviously don't live anywhere near a real traffic source, or you would very quickly realize that it's 100% impossible to slow down enough without using your brakes. I don't care if you shifted from 6th to 1st. Not gonna happen.
 

rickinAZ

Well-Known Member
First Name
Rick
Joined
Jan 2, 2020
Messages
1,917
Reaction score
2,072
Location
Phoenix
Vehicle(s)
2021 Rubicon Diesel
Occupation
Retired CFO. Mayo Clinic volunteer.
You guys obviously don't live anywhere near a real traffic source, or you would very quickly realize that it's 100% impossible to slow down enough without using your brakes. I don't care if you shifted from 6th to 1st. Not gonna happen.
Agreed. Although I think the shift from 6th to 1st may work better than you think...and, be more exciting.
 

bravelion

Well-Known Member
First Name
Steve
Joined
Jan 4, 2020
Messages
75
Reaction score
36
Location
Austin, TX
Vehicle(s)
2020 JLUR
Occupation
Real Estate Investor
You guys obviously don't live anywhere near a real traffic source, or you would very quickly realize that it's 100% impossible to slow down enough without using your brakes. I don't care if you shifted from 6th to 1st. Not gonna happen.
Well, I live in Austin TX, some of the worst traffic anywhere. And I drive between here and Dallas several times a year on IH35, on the busiest stretch of that highway in the US.

This argument isn't the hill I want to die on, I'm simply reporting the facts regarding how my specific ACC functions on my particular 8-speed Jeep. I noticed and observed it when I towed a trailer and could see the glow of the brakelights, or absence thereof, in various driving scenarios. I reported upthread about when I saw brake lights come on (when brakes were used).

I could be wrong and it may work differently on newer models.
 

Karl_in_Chicago

Well-Known Member
First Name
Karl
Joined
Nov 4, 2017
Messages
831
Reaction score
806
Location
Chicago
Vehicle(s)
Acura RL, Chevrolet Corvette, Harley-Davidson FLHTC Electra-Glide Classic
If your power of recollection isn’t accurate, don’t rely on it.
Saying it "feels" like the brakes are coming on isn't the same thing as saying "the brakes came on" - but whatever floats your boat.
 

aldo98229

Well-Known Member
First Name
Aldo
Joined
Nov 16, 2019
Messages
5,596
Reaction score
12,251
Location
Bellingham, WA
Vehicle(s)
2018 Jeep Wrangler Unlimited Sahara, 2018 Fiat 124 Spider Abarth
Occupation
Market Research
Vehicle Showcase
2
I am so glad I didn't get that option
 

cjaama

Well-Known Member
Joined
Sep 24, 2018
Messages
397
Reaction score
318
Location
Albany, NY
Vehicle(s)
2019 JLUR
Saying it "feels" like the brakes are coming on isn't the same thing as saying "the brakes came on" - but whatever floats your boat.
No shit. That was exactly the source of his confusion and the reason he started this thread.
 

brbutler

Well-Known Member
First Name
Brian
Joined
Mar 22, 2019
Messages
45
Reaction score
87
Location
Woburn MA
Vehicle(s)
2020 JLU Sahara 6-speed, 2016 VW GTI 6-speed, 1984 Porsche 928S 5-speed
Most modern vehicles activate the brake lights via pressure switches on the master cylinder. And, most ACC systems (all, I would suspect) will apply the brakes electronically via the ABS pump (applying braking system hydraulic pressure) when needed to maintain the minimum following distance selected, thus activating the brake lights. On my Durango, I could see the brake lights activating while using ACC when traffic ahead would slow at a faster rate than just coasting down (I had bikes on the back and could see the reflection in the mirror). The lights do not come on when ACC adjusts speed by coasting or engine braking, only when the ACC applies brake pressure. Basically the same scenarios as when driving without ACC.
 
Advertisement

Gibson Leatherworks
 
Advertisement
Top