I was on the freeway going about 65mph. I had the adaptive cruise control engaged. There were no cars in front of me nor in the rear There was a train to my right about 100 yards away. We were traveling parallel to one another. The train was going a bit faster than I.

All of a sudden the car braked on its own. It slows very quick from 65 to about 30 in what seemed like fractions of a second. I saw a red light flash in the instrument cluster and a loud waring buzzer sounded. I could not read the warning light as it went too too fast. As soon as I felt the car slow I turned off the cruise control and the car stopped braking.

Given there were no ( NONE) cars in from or in the rear, what could cause this? If there was a car on my rear bumper it would have hit me. Scary... to say the least.

The train was off to the right so I don't see how the radar could have picked up on that.

Maybe a bird or shadow from the train??

Any thoughts?

 

Do you not have a safety body you can report it to? (We do, and I would if it happened to me here.)

 

JozJag, that would definitely make you butt eat some cotton. So, I can understand where you are coming from. The only thing that I could possibly see is if there was a piece of paper or a bird and that caused the car to think that something suddenly came up in front of you and it wanted to slow the car. I don't think a shadow would cause the system to actuate. If that was the case, then you should have it activate every time you go under an overpass during the day.

I will be curious what others say about this.

 

The system must have thought that something crossed into the path of the beam scanning the road in front of you. It could be an electrical glitch, or something physical did actually block the beam for long enough for the car to engage hard breaking. Which setting were you on with the adaptive cruise control, was the road level and straight?

 

Can one of you tell me where the link is to input my vehicle info.? IE. the signature line...

 

The setting was on greatest distance front the car in front ( which there was none) and the roadway was level and straight.

 

The only time this has happened to me was when a car pulled in front of me whilst there was another car in the blind spot (well, the blind spot sensor was illuminated). What flashed on the dash was "Driver Intervention Required" with buzzers bells and lights. I don't have lane assist or anything, just ACC and blind spot, but in my case I definitely had other cars on the sensors. Mayhap it somehow thought that you were wandering out of your lane? (Anyone know how it decides when this is occurring - I guess it could have got confused by a glitch in the lane markings?)

 

Jozjag, I was doing a little looking through the service manual that I have (it is for 2011 vehicles) and it doesn't talk about the collision avoidance system of the car. But, what I did find interesting is that cars with ACC also have a feature known as "Emergency Brake Prefill". In short, what this system does is if the accelerator pedal is rapidly released, it will pre-fill the brake system with a slight amount of pressure to allow the driver a quicker brake pedal response. It is a very small amount. But, if this happened to have a glitch when the car released the amount of throttle as you were driving, I could see where that may cause the brakes to do what they did. Granted, I am putting more money on a piece of paper or say weeks on the side of the road that were moving in the wind to cause the car to think something was jumping out in front of the vehicle.

I thought you might find this of interest

 

Computers are great when they work. When they don't they aren't worth the plastic they are made of !!!

Sorry, but I'll stick with manual controls. Thank You.

Sound like the start of a good lawsuit.

 

Thermo, you may be on to something with the gas pad thing... As best as I can recall, I do think I had just released the gas ged because I wanted to slow down to see how fast that train was traveling. It is passing me and I was curious. I did not hit the brake because I did not want to disengage the cruise control. You are a good detective my friend... Thank you!

 

Jacob, Thank god there was no accident and I can not ( to the best of my knowledge) prove this happened. I doubt a law suit would be successful. But, one never knows...

 

JozjJag, if you are thinking it is the gas pedal trick, you can get out on a lonely country road and get the car up to say 60 mph and then get on the gas a little bit more, then quickly get off the gas. You can then be ready for the car to suddenly brake. You can do this say 5 or 10 times and see if the problem comes back. Then you can atleast have some comfort in knowing it was a one time thing and that it doesn't happen all the time. The big thing is making sure you have no one behind you when you try this. Hence why country roads are a wonderful thing.

 

Thermo. Thank you once again my friend. Yes, I plan on doing exactly that when the wife is not with me....