Recently purchased a used 2017 Toyota Corolla. During the test drive I did not attempt to use the cruise control as it was only driven on city or small highways. Travel with the car at those locations has been good. Yesterday while on a freeway, I used the cruise control. It started out okay, but when I got to a downhill or uphill location, the car engine got very loud. The rpm-??s revved to an extremely high level and the car accelerated and kept accelerating beyond the cruise set speed. I became very scared and didn-??t know what was happening. Luckily I had quick thinking to hit the brakes immediately. I actually pulled over and stopped due to the issue and my nerves. The engine looked okay so once calmed, I began traveling again. I wanted to use the cruise on the freeway, so attempted a second time later. The same exact thing happened in the uphill / downhill scenario. I realized there is something wrong and it is not a good issue at all! This morning I began researching things related to the car. Prior to my purchase, I had checked for any outstanding recalls (which there were none) and problems people may have had with this car. There were no general concerning things I saw. This morning I began searches specific to cruise control issues and found discussions and even videos pertaining to cruise problems. People mention an array of scenarios and possible reasons such as the brake pedal sensor not working. Then I came across this site where other people described the same exact problem and safety concern of mine. I agree with all of them that it is definitely scary and thank goodness the brake works otherwise it would be a MAJOR safety concern!! I am now concerned and wondering why after many people have problems with this, there is not a fix or something being done?

- Reedsburg, WI, USA

Vehicle went out of control in regards of speed when traveling downhill with cruise control on. Vehicle began heavily decelerating and accelerating along with high engine rpm. This is extremely dangerous and I am unable to use cruise control because of it.

- Johns Island, SC, USA

I had to drive around 600 miles to and from family funeral. As others have reported the cruise control on a down hill slope goes out of control. As I reached the top of a hill and started down the cruise control would accelerate to 4000 RPM ( it is really loud) the speed would start increasing and go 15-20 mph over what the cruise control speed was set at. I had to turn off the cruise control to regain control over the speed. I was afraid that something might happen if I did not. Where it seemed my car should down shift it was not. Something is wrong with the programming of the cruise control. This should not happen on a decline. Also, at one point when I was in the left lane and a car passed me on the right, my car slowed down really quickly. If someone had been behind me it could have caused a serious accident. This is my fourth Toyota and I have never had these problems before.

- Coon Rapids, MN, USA

When going down hill, the cruise control races the engine into high RPM (4000+ RPM) rather than slowing the engine and controlling the car speed. It has done this since it was new.

- Johnson City, TX, USA

When cruise control engaged, if it hits a level or down hill it appears to down shift, but continue to speed up. It should just reduce the fuel to slow down. This appears to be a program problem. This happens at all speeds. It was bought used from a Toyota dealer. I have not asked the service department yet.

- Fort Worth, TX, USA

While driving down a downgrade with the cruise control engaged and set to 65mph, the cvt transmission downshifts, the rpms increased and the vehicle accelerated to well over the speed limit. It felt like I was losing control. I had to activate the brakes to disengage the cruise control in order to reduce my speed to below the posted speed limit. I tried it again on another downgrade and the same situation was duplicated. The car will also engage rpms when you are downgrading or upgrading in cruise control I did not take the car into a dealer since the issue has been reported to dealerships with a solution to this problem.

- Pennington Gap, VA, USA

When going downhill on cruise control my Corolla's RPM's go up to 5000 and instead of keeping stable speeds it increases the speeds. I feel like I can't control my vehicle when this happens. This is a huge safety issue. I'm not sure if something needs to be re-programmed but I've seen so many complaints on this issue. I wouldn't be surprised if a wreck has happened because of this. Toyota needs to be forced to fix this issue before someone seriously gets hurt or dies.

- Paducah, KY, USA

Disappointed with Toyota on this, last one I will purchase if they are unable to provide a fix! while in motion on every occasion the cruise control is engaged and the vehicle is on a decline the cruise control does not maintain the set speed. This is the first time of 4 other Corolla's I have owned that responded like this. Depending on the severity of the decline the speed will increase from 5 to 15 mph and the engine revs to 4,000 rpms in an attempt to maintain speed. Adam's Toyota dealership has stated that this is a normal occurrence for all 2017 Corolla's cvt's and I maintain it's not and cruise is useless therefore I should be reimbursed. The cruise control in all other vehicles (prior Corolla's and other makes) I have owned has maintained a consistent speed no matter the road being traveled. Since I have owned this vehicle this issue has occurred every time I have engaged the cruise control. Others online have complaints on this issue as well. Toyota please provide fix

- Excelsior Springs, MO, USA

The cvt transmission make a sound unknow the dealer say me that is all normal in the car for me is not normal other cars contain cvt transmission and this sound not make in others cvt transmission is more making sound in climb and when on air conditioner

- Barranquitas, PR, USA

While coming out of a revered position, I was driving forward and my brakes vibrated. This caused my car to stall while in the driving position.

- Houston, TX, USA

Red brake light, ABS, vsc, power steering, and mil lights came on. Dtc's U0129.

- Mesquite, NV, USA

As others have reported the cruise control on a down hill slope goes out of control. As I reach the top of the hill and start down the cruise control will accelerate to 4000 RPM and the speed will increase 10-15 mph over what the cruise control is set at. I must turn off the cruise control to regain control over the speed. Something is wrong with the programming of the cruise control. On down hill the cruise control should be reducing fuel to maintain speed not increase it. I am a police officer and this cruise control is a hazard.

- Draper, UT, USA

While driving down a downgrade with the cruise control engaged and set to 65mph, the cvt transmission seemed to downshift, the RPM's increased and the vehicle accelerated to well over the speed limit. It felt like I was losing control. I had to activate the brakes to disengage the cruise control in order to reduce my speed to below the posted speed limit. I tried it again on another downgrade and the same situation was duplicated. I did not take the car into a dealer since the issue has been reported to dealerships with a solution to this problem.

- Venice, FL, USA

Bought the car last April, it has given me no problems, until now. The car start to loose acceleration when driving almost got into two car accident on the road, called Toyota but they want to charge me to inspect the car, the car seems to be stuck on gears like if it was on neatrual.

- Beverly Hills Ca, CA, USA

Was driving in middle lane of interstate 10 when vehicle lost power. Car would not accelerate. Car coasted for approx. 5 minutes. Had to put on emergency flasher, put car in park to restart engine. Cars coming up behind me doing 75/80/85 miles per hour and had to swerve immediately to keep from hitting my vehicle. I had a friend in passenger seat and we were both scared for our lives. To this day, I am afraid to drive on interstate or any other busy highway because Toyota said they could not find any problem.

- Carriere, MS, USA

Adaptive cruise control causes the car to down-shift unnecessarily on a straight downhill grade and sometimes increases the speed by as much as 8-10 mph. I feel out of control, which is dangerous. A Toyota technician has confirmed the same behavior on another 2017 Corolla. On one occasion, on a freeway downhill where the speed could have easily been controlled by letting off the gas, the car downshifted to D3, revs went to about 4000, and the speed increased to 70mph - when it was set to about 62. On another occasion, on a relatively flat, straight freeway road, it again downshifted for no apparent reason, and the speed again increased over the set speed (of course the revs were higher again). In both of the above cases, there was no car or other obstacle in front of me that should cause the car to slow down. I've seen the adaptive cruise respond to a car too close so know how that feels.

- Sunnyvale, CA, USA

My car was struck by a car spinning out of control mainly the drivers side door center post and rear door. I think the car is totaled. The passenger rear wheel is bent from the impact. None of the air bags deployed. The police officers that worked the accident was astonished. He said they should have deployed. My car was moving about 15mph the car that hit mine was spinning very fast. The roads were slick and it was raining. The impact was about 40 to 60mph at least.

- Rome, GA, USA

The cruise control is just awful and has been since I bought the car brand new in December 2016. Just as several others have described, it cannot control the speed when going down hill. It raises the RPM's trying to slow the car down, but it isn't very effective. I've never had another car or another Toyota have such poor speed control. So much, that I don't even bother trying to use it anymore. A cop isn't going to listen to "my cruise control wasn't working right" if I get pulled over. The brakes already feel like they are wearing out at 26K miles. My 13 Camry had 30K and the brakes still felt brand new. Same with the 15 Sentra I had. The suspension feels rougher and is starting to make noises already. This car shouldn't feel like it has 60K miles on it already.

- Brackenridge, PA, USA

The vehicle does this 100% of the time. When on the adaptive cruise control on the interstate there are occasions where the cruise will go 14 mph above the set limit and the engine is at 4000 RPM or higher. I typically drive at 65 mph on the interstate; this is causing me to go to over 75 mph while the system is trying to recover back to 65mph. I also own a 2017 Toyota rav4 and drive the same roads; the cruise is 'rock steady'. it holds at a constant 65mph.

- Mars, PA, USA

Car speeds up at stop or low speeds on highway and streets stop and go traffic

- Croton On Hudson, NY, USA