Cruise Control - Explained

How does cruise control work? What is cruise control? This video explains how cruise control keeps a car running at a constant speed. It explains the mechanical system that utilizes a vacuum actuator to control the throttle.
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[@chengyoujiang6076]

11 years later, still very useful for understanding basic principles - well done!!

[@maazshahid8920]

Can you explain how cruise control gets deactivated automatically when brakes are pressed?

[@EngineeringExplained]

You're welcome, glad to have people like you learning and appreciating the effort! :)

[@aryesegal1988]

Hey, you're a fellow to the trade, I'm a ME as well..! Got nothing but respect and appreciation for the clear and amusing way you teach these quite-difficult-to-understand concepts... ;)

[@EngineeringExplained]

Yes, they both help in determining the air/fuel ratio, as well as the IAT (intake air temperature) sensor.

[@robertsulley]

I arrived at this video on a search to find out why cruise control system, even some after-market ones, use vacuum based actuators. I'm still not 100%, but I think your point is valid, it's a legacy thing. The vacuum is there already, it's powerful and fast and relatively simple to control. Something that possible can't be said about the electronics available back in the day. Great vid btw!

[@EngineeringExplained]

Great question! Diesel would have to regulate the amount of fuel being injected. When it checks the vehicle speed and it is below the needed speed, more fuel would be injected. When the vehicle speed is greater than the set speed, the fuel injection would be reduced.

[@EngineeringExplained]

That seems to make sense. The only way it would prevent you from exceeding the limit on a considerable downhill slope would be to use the brakes, as engine braking can only do so much. It will, however, increase the amount the throttle is open if you are going uphill, to keep your speed up.

[@czech27]

very well explained. Thank you

[@EngineeringExplained]

Assuming it's automatic, this doesn't sound too uncommon. Press the gas and it revs up a certain amount, the torque converter is spinning a bit faster than the transmission. As the transmission speeds up to the speed of the TC, your RPM would remain the same. Once they match they could increase together, like with manual transmissions.

[@desertfox2020]

I figured. My truck is a 99 so I know what you mean. Sometimes mine will drop 10 mph on a hill it actually needs to increase the throttle and doesn't, and then will speed up to 10 over by the crest like you said. I only use it on 2+ hour drives where I really need it because of this. Thanks for the reply and keep making awesome videos.

[@EngineeringExplained]

I have referenced it numerous times. It is the first video of my first playlist, or you can simply search youtube for "Car Engines - Explained." Also, when you reply to my comments please hover over the comment with your mouse, and click reply. It's hard to follow the thread when you just create a new comment. I would recommend for you to go to my website (link is in the description) and start with lesson one. Watch the videos in the order I show.

[@aryesegal1988]

Another great video, Jason. Thanks for all the time and effort you're taking to film and upload these, we (or at least I) appreciate it A LOT! :) Keep up the great work..! -Arye.

[@EngineeringExplained]

Not sure, I'm sure it varies and can now be pretty instantaneous. For example, some ABS systems can alter the brakes 30 times in a second, or more. Something like throttle control seems like it could be even more adjustments per second.

[@EngineeringExplained]

Depends of course, if your speed is all over the place, it will likely save you. If you're pretty consistent then it shouldn't matter too much. Some provide excess gas at times, such as accelerating up a hill to maintain speed. I usually allow my car to drop a few mph when going uphill and then regain the speed once going downhill, in order to save energy.

[@EngineeringExplained]

I believe they do make cruise control kits. Try searching your make and model as well as "cruise control kit" on google.

[@EngineeringExplained]

Interesting, I don't know. I'd check your manual, if you still have it, or read on forums of other people who have the same car.

[@EngineeringExplained]

True, they do now have cruise control that remains a specific distance behind a certain car. This would certainly require brakes in some situations. Thanks for pointing that out.

[@ImKindaPanda]

your help me with my future in the car world i love you! auto tech forever! car lover plz don't stop making videos

[@EngineeringExplained]

There are some cars that can do this yes, just like when approaching something without the brakes applied, and having them applied automatically.

[@EngineeringExplained]

When the piston moves down during the intake stroke, it creates a vacuum, thus it pulls in air.

[@EfeezyLopeezy]

i always asked myself how cruise control works great explanation!

[@metodraginii]

AMAZING VID!!! So what are the sensors you necessarily need to have for measuring the incoming air and the fuel quantity in a every-day car? In yours you have the MAP airflow sensor and the TPS and they are both for the same purpose, am i correct?

[@EngineeringExplained]

Thanks! Yep, definitely better ways of doing it now.

[@EngineeringExplained]

So you're saying after a long day of school you like to... keep learning? I admire that!

[@mEandthEgamE]

As someone who has no knowledge of engineering this was clear and made sense

[@bouletmarc]

Thats explain a lots on how you are informed about your own mechanics that your car have... Your car (Honda under 2000's and acura under 2001's) dont use a speed sensor reading for the cruise control at all, you can have a broken speed sensor and keeping cruise like normally, it is definitly only working with atmospheric and intake pressure. Your video have learn me the principle of the system, but you are at the same time explainning something that doesn't match your car and you use your car as exemple

[@EngineeringExplained]

Welcome!

[@EngineeringExplained]

Not sure how all of them work. I do not think many incorporate braking. Mine, for example, will let off the gas completely going downhill if the car exceeds the set speed. But it will not prevent it from further passing this speed if gravity is stronger than the resistance, in other words, it's possible for my car to exceed the set speed by going downhill.

[@MrFordy90]

I used to work at Honda.... the main give away is that bright blue washer bottle cap! but everything else of the car... the design and layout of the engine bay

[@EngineeringExplained]

I would bet on the computer. It's frustrating for my car as well, which is a manual. It loves to floor it when I go up a hill when I know it's not necessary, only to overshoot the target speed once the vehicle crests the top of the hill. I would imagine modern cars can do it better than mine though.

[@palak0]

I find very interesting (clever) how intricate the design of the actuator is. There must be a reason to do this instead of a simple servo, which one would think would be more precise and reliable. Do you happen to know if that wouldn't work or why? Thanks for the great video and channel, I'm learning loads.

[@dahaproject3498]

for japanese car, JDM or non JDM you can buy pivot 3D cruise control. I used for my hilux 2KD engine. awesome with OEM cruise switch

[@dexterherl268]

We are trying to figure out if we can install a cruise control box off of a 1994 Chevy pickup on a Peterbilt. Are we going to have to put the ecm off the pickup in the truck to make this work?

[@bwinarno]

it's very clear explanation, how does cruise control work? thank you

[@EngineeringExplained]

Thanks! I don't have any plans on stopping. :)

[@alalal123421]

glad you never did still enjoying all of your content and revisiting thank you sir

[@donotwantahandle1111]

I think on my car the cc button under the brake goes into some module which also controls the accelerator electronically?

[@richardemms3050]

Had an Audi 80 with cruise control, for a system as described it was very stable. Set it on the motorway and it would stay exactly at the same speed, even with a sat nav speedo it would not move even 1mph all day.

[@sikhswim]

Nice work. Your next video should explain the details of PID control ;)

[@ReallyRyan.]

Could you possibly do a video on how dual engined cars work? I've seen them in muscle car shows and I've been wondering, for some time now, how they could possibly drive.

[@desertfox2020]

My cruise control enjoys revving the engine much higher than needed when going up hills. Sometimes it will hit 3 grand on a hill I could go up without the TCC unlocking if I were controlling the speed myself. Is this a slack cable or just the computer being sloppy?

[@drzulfiqar1272]

My car cruise control works till 110 kmph speed but it does not work above 110 kmph, Please guide me what could be the problem

[@EngineeringExplained]

99 integra ls

[@EngineeringExplained]

Click on my username, which will bring you to my channel page. Then click on the first playlist, and it's the first video listed. Naturally aspirated just means there is no use of forced induction (no turbocharger, supercharger, or other device used to increase pressure).

[@ivanpowers6436]

Nice video, but I was wondering how the old one work? Like on the 1979 Caprice I have. No ECU. It has a box that hooks up to the speedo cable from the trans and then goes into the gauge cluster. I know there's most likely some neat stuff going on in there. If I don't find out soon I'm going to have to take it apart. I must know what's inside there. Anyway do you know of any web pages I could go to or videos I could watch to explain what's going on in there. Thanks

[@Drifting50]

Would I be correct in saying that the vacuum created in the intake manifold (that is used for things like cruise control and vacuum-assisted power braking) is created by the intake valve opening in junction with the piston moving downwards (in the "intake" stroke of a combustion engine), which, when the piston moves downwards, creates a low pressure area that air rushes in to fill, thus creating a vacuum in the intake manifold?

[@EngineeringExplained]

You would be correct.

[@Maxwell1989]

​@@EngineeringExplained 2014 Nissan rogue and we're going up a slight grade we set it at 60 MPH it is at 3,000 RPM but it was increasing speed up to 65 mph is that normal??

[@juarez8810]

Hi, Have you got any troubleshooting vids? Thanks and keep up the good work.

[@Adventure.AS.25]

Could you explain how cruise control works going downhill. Even on fairly long, steep Interstate descents the cruise control on my 2015 Jeep Wrangler keeps the speed from increasing. Does this involve braking too?

[@senduran35]

Do you have a video for this explanation? if you have can you give a link for that please

[@katiecole8681]

Question - can you tell me the exact type of cruise control that you are referring to? is it the ECU?

[@senduran35]

Can you a link for the naturally aspirated engine, I couldn't find from engine channel please

[@Ameya0810]

Will modern cars also automatically apply the brakes if it is over the set speed?

[@avid521]

Hi! Where does the CC module read the vehicle speed from? Should i connect the vehicle speed INPUT of the CC to Vehicle speed OUT of ABS module or should I directly pull 1 wire from one of the four Wheel speed sensors?

[@gordon8130]

Hi Jason, could I reprogram minimum set speed for example if the cruise don't work under 50km/h but I want to set it to work at 40 ??. Thanks

[@iiTsMacca]

@EngineeringExplained YES! Thank you so much!

[@akshayinarkar8327]

We want to use cruise control mechanism in two wheeler by using stepper motor. so can u tell us procedure to how to do it?

[@senduran35]

Can you explain the naturally aspirated engine, please

[@praveenkumarhota7570]

hi dude. I am also a mechanical engineer.can you plz explain about quadrajet carburetor working

[@EngineeringExplained]

How'd ya know?

[@ianmarquez7691]

Can you teach me the connection of cruise control on my toyota yaris 2017 a/t.?

[@dakotak8437]

So does haveing a abs light come on anything to do with crouis control bc mine stoped working right after the abs light came on

[@ianhellsing3327]

great video thank you for the knowledge

[@EngineeringExplained]

You can make them any shape you'd like. :)

[@EngineeringExplained]

Yes, it's controlled by the actuator.

[@itftcomputers]

I need your help please! I have a honda Jazz 2009 without the CC, but I really need it, so I was thinking if I get the steering column with the CC controls, what other parts would I need from the scrap yard in order to get the CC working? It's a manual gearbox by the way! And even if I get all the parts, would that work without the ECU or whatever control the CC replacement? Thank you very much, great video!

[@PavelShevchuk]

In case of your Integra, that's "overengineering explained". On older BMWs cruise control actuator sits directly on the throttle body.

[@carlotheatheist]

How cruise control disable if you press the brake pedal?

[@praveenkumarhota7570]

i think carburetors only used in gasoline engine.but my car has diesel engine and it has quadrajet carburetor.that's way i m bit confused that how it works.because carburetor mixes air-fuel ratio. and delivers it where as diesel engine has injection system.

[@stopthephilosophicalzombie9017]

@engineering explained Hey I'm trying to MacGyver an actuator for a sewing machine foot pedal for a double amputee and was thinking of using a cruise control actuator from the junk yard as a cheap alternative to a servo motor or linear actuator. Do you think this might work?

[@EngineeringExplained]

I have a video on carburetors, search my channel. A quadrajet just has four barrels rather than 1 as my video does.

[@XHikotheproX]

Great explanation! like always.

[@EngineeringExplained]

Haha, definitely an easier approach. I guess it depends on space ultimately.

[@TheMrinallabh]

u r my inspiration

[@shemissashanti]

wow! give him his flowers!

[@mymusicaccount1456]

What would cause CC to go WOT and run away when activated? Jeep Cherokee.

[@shavuklia7731]

You're awesome, man - thanks for the vid!

[@alanvlogs_]

Finally I realised what is cruise control 🙂

[@dannyr403]

Every car I've owned, the cruise control only works if I'm doing a minimum speed, round about 30 mph. I know it's supposed to be that way, but, hypothetically, if someone wanted to MacGyver their cruise control to work at say 20 - 25 mph, could they?

[@yasfam3700]

Hi, i have 2.0 6 speed A/T. Normally i put my cruise at 130kph. After set to 130, i shift gear from D to manual. It shows gear 6. So if theres small angle of uphill it will not downshift automatically as if it is in D. The result is speed will go down to lets say 120. For me its not a big deal since i dont want the engine rev because sometimes it shift to gear 4 (in D) and speed will comes up after the hill. And i dont really need to keep speed lock to exact 130 actually. Thats from my point of view. But do you know is it safe for engine or transmission if i am doing this way?

[@juanojeda5548]

I got a question I have a 2019 nissan versa manual transmission I want to install a cruise control but my car its drive by wire does this its possible?

[@senduran35]

Then how does it get the pressure?

[@rezaarkan2234]

Perfect 👌🏻👌🏻

[@CRFbadass]

Dude you're awesome! We're like, the same! lol I piss my girlfriend off SO much talking about vehicles...

[@giadinhphongchuc]

very good. thanks o lot

[@iiTsMacca]

Can someone please explain what understeer and oversteer is? :p

[@StraigtEdgeMember]

thanks for that

[@EngineeringExplained]

Check out my video "stability control." I've explained it there :)

[@EfeezyLopeezy]

*Worked

[@beautifulpaintingwi]

Thanks allot bro. for the vids. they really help out. :)

[@EngineeringExplained]

Haha yes, I can relate.

[@livetoridemyxlh]

I have a 1997 Civic. When I set the cruise control, it accelerates past the set speed. It even keeps going for a few seconds after I apply the brake to stop it. What do you think could be the problem? I've replaced the actuator and vacuum lines. I'm about to replace the speed sensor.

[@noahdecoteau6381]

I have this exact same problem. Were you able to fix it?

[@jorgefonseca9225]

nice vedeo you are really goot just keep going

[@capesaver]

I noticed when my 2008 Honda Accord is in cruise control mode and I am driving on the road with slope more than 30 degree, I cannot de-accelerate to reduce my car speed, it works fine going uphill and flat road, do you know what is causing this?

[@faheemd50]

change the The switch car will fix, I had the same problem.

[@moosasyed1011]

Where is the full video?

[@praveenkumarhota7570]

my car is Tata Indica Vista.It has four cylinder diesel engine with quadrajet.

[@sotaros93]

what about diesel?

[@SJSOmar]

What if I don’t have a throttle cable mine is electronically actuated

[@FarmYardGaming]

Looked complex at first but it makes sense now.

[@darkfireBikes]

My truck seems much different. It's all cable actuated, but there's 2 going to the throttle body. One directly to to the gas pedal, one directly to the cruise control. But the cruise control is a box with what seems to be a motor in it. There's a ton of connectors coming out of it. So it's not fly by wire, but works like it. (2000 mazda b4000)

[@EngineeringExplained]

That's how you found out, not how he knew.

[@dondjones3]

Can i ask what you drive???