2017 TOYOTA COROLLA Forward Collision Avoidance Adaptive Cruise Control Problems

When the cruise control is set and I go down hill my car increases the speed by 8 mph faster than the set speed. My car also makes a loud grinding noise when it does this. I spoke with different Toyota auto employees and some say that the increase in speed and noise are normal and others say the opposite. I have been in many cars driving with cruise control on and never experienced this.

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...