On interstate in western Maryland and West Virginia, road curves to left, going uphill (steep) at 70 mph and 4000+ RPM in drive, 3 lanes, truck in "slow" right lane (40mph), Corolla in middle lane, left lane empty. Safet sense "sees" truck and hits brakes. No one behind, thanks. Possible rear end collusion. Serious safety fault. Difficult for Corolla to regain speed. Does not happen on right curve as those vehicles in left lane are moving faster than Corolla.

- Medford, NJ, USA

The vehicle was traveling in the left lane of a divided 4 lane highway at a speed of 55 mph with the speed control and radar engaged. The road curved slightly to the right. The vehicle approached a car stopped in the left turn lane in the median - not it the lane of travel. Due to the curvature of the road, the radar detected the stopped vehicle and apparently believed it to be in the path of travel. The radar/speed control sounded its "collision alarm" and rapidly decelerated approximately 10 - 15 mph before I could disengage it and regain control. Had there been a vehicle following me this could have resulted in a collision as a following driver would have seen that the lane of travel was clear and would have no reason to expect my vehicle to suddenly decelerate. I have experienced similar issues when a vehicle in front of me turns right or left at an intersection. I can see that the vehicle is turning and I know how long it will take to clear the travel lane. The radar speed control system seems to detect the slowing vehicle but takes a long time to process what is happening. The speed control will abruptly decelerate the vehicle after the turning vehicle is well out of the intersection. Again, the sudden deceleration without apparent traffic conditions to warrent such action are a hazard to the vehicle and any following vehicles. I took the vehicle to the service department at at Toyota of goldsboro (nc) on October 23, 2017. Their opinion was that the speed control/radar was "operating as designed."

- Clayton, NC, USA

Speed control engaged going downhill on highway at 60 mph - car accelerates very quickly to over 70 mph and the tac goes to 4500. To disengage I either turnoff speed control or brake. This happened four times today. I have never had a Toyota act like this. Usually speed control maintains the speed uphilll or downhilll in a very small range and never races the engine. This is very dangerous and I will not use speed control until I can get this fixed. Taking to Toyota Monday. I noticed that there are quite a few complaints on the internet about this exact problem.

- Johns Creek, GA, USA

The contact owns a 2017 Toyota Corolla. The contact stated that while the cruise control was activated at 65 mph, the dynamic radar feature activated violently. There was no vehicle in front of the contacts vehicle at that time that should have activated the dynamic radar. The dealer (Toyota of easley, 5643 calhoun memorial hwy, easley, SC 29640, (864) 855-2233) was notified. The manufacturer was also notified of the failure. The approximate failure mileage was 700.

- Pelzer, SC, USA

I just purchased a 2017 Corolla xse in Feb 2017. The first time it happened I had the cruise control on and was traveling to work at 05:15, and I came to an overpass and on the way down the normal overpass over a cross street, I heard the engine rev and I looked at the tach, and it was at 5000 RPM. I was startled. The same thing happened at the next overpass. This time it was 4000 RPM almost at the bottom of this rather short average downhill. This is still happening, but occasionally it does not. How could this possibly be correct. I can control the speed quite nicely with my foot on the accelerator without hardly any variation of my RPM's. this just doesn't make sense. I am not talking about a long downhill road that has a lane for trucks on the right, where they would have to downshift to maintain a safe speed, this is just overpasses on a freeway system. I asked my salesman, and he said that it was probably normal, and I said how could it be normal for this thing to rev at 5000 RPM on a houston freeway? I only have 5000 miles on this car. This will definitely affect the mileage. I am beside myself at this point.

- Seattle, WA, USA

On 3/22/17 I was driving an enterprise rental car into an apartment complex and pulled in front of the leasing office to park. While stepping on the brake pedal the car did not stop and it suddenly accelerated causing the car to crash into the pillars of the leasing office with force. Airbags deployed and my passenger and I had to crawl out of the rear passenger door to escape the vehicle. We are lucky to be alive and escape with minor injuries. There are drag skid marks on the ground from the rear wheels. Upon collision the engine shut off even though the key was in the run position..

- San Diego, CA, USA

While using cruise control on fairly level roadway, (rural road) at a speed of 45 mph, the RPM were about 1500, but increased suddenly to about 4500 RPM. After awhile the RPM would drop back down to normal for the speed situation. This occurs also at highway speed of 60 mph in our area. This occurrence has happened many times. Have returned to dealer twice now. Problem was observed by service manager and local Toyota rep who was in town for local auto show. Car was analyzed and data send to engineer in California who later said car is behaving normal. I found that hard to believe as both loaner cars (2017 Corolla) did not behave in this dangerous fashion. I feel this quick brush off by the engineer (tanaka) who is only observing data and not having to drive this car is wrong. I feel the computer should be adjusted for the cvt to solve this problem. Wife does not feel safe driving this vehicle. We have taken 3 videos to document this event.

- Auburn Township, OH, USA

When the cruise control is engaged and the vehicle is on a decline the cruise control does not maintain the set speed. Depending on the severity of the decline the speed will increase from 5 to 15 mph. When using the accelerator pedal and maintaining the exact same pressure the vehicle only increases speed minimally (2 to 3 mph) on the decline. When in cruise control the speed increase is very drastic. The Toyota dealership has stated that this is a normal occurrence and that they have tested several same model and year Toyota vehicles and all have the same speeding tendencies so this is normal. The dealership stated that the fix is to engage the manual transmission mode to use the engine compression to slow the vehicle down. I have followed there advice and this does not rectify the problem. The cruise control in all vehicles I have owned is used to maintain a consistent speed no matter the terrain being traversed. This issue has occurred every time we have engaged the cruise control on the vehicle while driving on a highway that has a decline.

- Elma, WA, USA