Cruise control out of control

What Drive Mode? Eco, Normal, Pwr?

 

There are two types of Cruise (Dynamic Radar and Regular Cruise) Dynamic has some strange behaviors compared to Regular Cruise. Hold the Cruise Control On - Off switch for 5 seconds to activate the Regular Cruise Control. If the Prime still accelerates to fast for your liking when using resume, you can always use the Go Pedal to accelerate closer to your set speed before hitting the resume lever.

 

That seems to be industry-wide. I suspect if they made it more leisurely someone else would be complaining "what's taking so long".

It bugs me too; there's something inherently unnerving, when a car accelerates all by itself. My work around, is to rarely if ever use "resume". Instead I'll just accelerate manually, then tap set again. Or hit resume when I've almost got to my previous target speed.

 

IMHO; that's normal behavior. I use dynamic cruise, and usually set it for 68 mph - if the car in front of you is traveling <55 mph; your dynamic cruise will automatically slow your car to 55 mph, with whatever spacing you've programmed. Once the car in front of you clears; your car will accelerate back to it's set speed. I don't know of any way of trimming the rate of acceleration; other than disengaging the cruse control.. Your problem is probably compounded by not adjusting the trailing distance and using it in heavy traffic.

It's a dumb computer that's doing what you told it to do; Not what you want it to do...

Hope this helps.

 

You can't please everyone. I do a lot of driving on dynamic CC (1 or 2 thousand miles) every month and find the acceleration when resuming CC is close to what I would do manually. There is nothing dangerous about it.

On the other hand, When I go from CC to brake to manual acceleration it is not as smooth as I would like. I'm used to it but my wife freaks. The solution is to disengage CC before hitting the brakes and then gas.

 

I think that's your problem right there. You have expectations based on previous experience with a different product. That happens all the time when people move from iPhone to Android or Starbucks to Peets coffee. They expect what they are used to from the previous products. Never mind that the behavior of the previous models might not be part of the design. It might just as easily be a side effect of how much power the car has available.

My 2017 does not usually rev into the red zone just to catch up with the car ahead of me. When it does, I don't worry about it because it takes only a matter of seconds to get back to my 'max speed' or to get close to the car that I'm following. I use the max following distance, so I almost never take it out of DCC while on the freeway at speed.

If you are frequently needing to take your car out of DCC and resuming it, maybe you are not driving it in the conditions where it's supposed to be used? Like mountains or city streets?

 

I doubt there's anything wrong with your car. This is purely conjecture since I do not drive a Prime, but could it be you're experiencing too rapid acceleration for your taste simply because of the instant torque of pure EV acceleration vs. HV acceleration? I understand from the Forum that the Prime accelerates much more briskly than a Prius Hybrid when in EV mode.

 

What other ways can we offer? I'm pretty sure Toyota is not going to change the behavior of the cruise control, especially since there are several ways to use it (or more importantly not use it) that should satisfy most drivers. I have my issues with the way dynamic cruise in certain situations too, mostly just behavior of other drivers though, so I'm much more comfortable using regular cruise when there is the possibility of experiencing the behavior I don't like when using dynamic cruise.

If you've registered at My Toyota there may be a way to report your issue there.

 

I just have to note that the topography where I drive includes numerous segments where cruise control must go well into the 'red area' just to maintain highway speeds, let alone resume back up to such speeds in finite or traffic-friendly time. If it was set to never go into the 'red area', then on some uphill segments it would necessarily bog down to well below the speed limit and prevailing traffic speeds.

Basic cruise control isn't smart enough to adjust for level vs various uphill roads, so must be configured to reach full engine power (or nearly so) if necessary, in order to do its job. If one prefers to lock out the 'red area' for flat topography, then one would need a more advanced adaptive cruise control that has knowledge of the topography ahead. Terrain-adaptive systems have been rolled out for commercial trucks, but I'm not yet aware of any for passenger cars.

 

you can talk to the dealer, have them take a ride with you, and a sienna or something else to compare.

you can call toyota corporate and open a case.

you can file a complaint online with nhtsa.