2013 Prius v (lowercase v for the Prius v wagon) cruise control unexpected acceleration

First let me say, I live in a city and don't get to use my cruise control daily but do use it when traveling down the highway. My vehicle has about 25,000 miles on it.
Twice this week, while driving down the highway with the cruise control set to approximately 70mph, the car accelerated in excess of the set speed. First time I found myself going 87 mph and hit the brakes. reset the cruise all seemed fine. 3 days later I was in cruise control again, going up a hill, the engine geared down as expected, but seemed to be accelerating beyond the setting. I did manage to look at the dash before hitting the brakes to see that the setting appeared to be 110 mph. Once again, brakes kicked off the cruise and I reset it and there was no problems for the remainder of the drive. Both situations happened on an up hill grade and while the cruise had been working fine till that point. The floor mat is not the issue, and no unintentional adjustments were made by the driver.
I called the dealership this morning and explained what had occurred and they knew of no problem. I am engineer and pretty methodical about my observations. I do realize that unless you can repeat something it is hard to diagnose. Hoping someone else out there has had a similar experience.

 

Good point. However, there was no other vehicles around me at the time and I was on a 6 lane highway. And since I was on cruise control setting at approximately 70 mph, I had no reason to believe it would be above the setting. As for the 110 mph, I doubt that this car could even go that fast much less on an uphill. I stated, "the setting appeared to be 110 mph" and not that my speed had increased to it.

 

Since this is a new issue, I'm just exploring possible solutions. I have only used the DRCC mode and will try the Std CC mode to see if that changes anything. Trying to make this repeatable or resolving the issue with any confidence will be the issue. I could not say with any confidence that the DR may have played a role in either case. First time was a surprise and the second time was not expected either. Now, I am at least cognitive of the issue. thanks

 

Air Boss, not sure what your point is yet but I'm sure you get there. I may have had it set at 75 mph. I believe the actual speed is irrelevant. The important part is that the vehicle was accelerating significantly beyond the CC set speed. I also, can't tell you what my actual vehicle speed was the second time this occurred. Hopefully, I can repeat problem and pay closer attention the next time to all of the details.

 

And there you have it. I don't necessarily disagree with you but I have been in many situations where the driver was going much faster than he or she realized. I will assume at this point you have no solutions or suggestions to help resolve the problem and will no longer need to comment on this subject. Thank you for your help.

 

The CC allows you to set the speed at whatever you desire, like any other CC does. If you review the prior threads, you will see that I have been using the DRCC. I have not tried the "std CC" setting yet as suggested by others. Hope I understood your questions.

 

Yes, you are correct, my CC is the same, just locks the speed and you can raise and lower incrementally from there. I was referring to the prior responses/reply as threads, apparently incorrect. Just didn't know if you had read them as well.

I am starting to understand why you choose the name you did. A more appropriate name might be Air_Bag. I can only hope to not hear from you.

 

When you set/lock the CC, the speed appears on the instrument panel. In this case, when the car began to accelerate beyond the CC set/locked speed, I happen to look and see what appeared to be 110 for the CC setting, prior to hitting the brakes and disengaging the CC. In both occurrences, the CC had been operating for 20+minutes and were in situations where the car was climbing a hill. After, disengaging the CC in both cases, I went on to reset the CC and continued to my destination without any issues.