Cruise Control Not Deactivated By Braking

It takes more brake pressure to release cruise control than any car I've ever had. I've learned to tap the pedal firmly to release rather than just pushing down slightly. That releases it before the brakes have a chance to apply and keeps the passengers heads from lolling about.

 

I have noticed that the cruise control requires a pretty significant amount of pressure on the brake pedal to deactivate. I haven't noticed that I slow down and speed back up...just the it doesn't disengage with a slight tap on the brake.

 

I have never had the CC reactivate itself after pressing the brakes, which I only use to control the speed of the car when using CC if I need to stop quickly. Otherwise, I find that using the CC stick to control speed avoids the jerkiness experienced when having to apply pressure with the brakes. I use the stick much more often to control CC than the brakes.

It sounds like what the OP is describing may be a problem with the car that needs to be seen about? I, too, am curious whether others have experienced the above issue. The brakes should disengage the CC until resumed or reset by the driver using the CC stick. Personally, I have not encountered this issue.

 

Eric, I have my top prius tech looking into the wiring of the cruise for you. Specifically, what sensor needs to be triggered in order to actually cancel the cruise. I'll post up here once I get the answer.

 

This is a duplicate of another thread. CC is disabled by a switch on the brake pedal arm. On the 2010, it takes a fair amount of pedal pressure to deactivate CC and likewise lite the brake lamps.

On the other hand, it is very easy to deactivate CC by pulling on the CC lever.

Tom

 

Ok, got some info. And are you pressing the brake pedal with a feather??? The cruise is turned off via the brake lights, i.e. lights come on, cruise shuts off. That is what I expected. So I jumped into a prius to see how sensitive the brake pedal is. It is sensitive, but I can definitely see how it could happen. It seems that the regen braking is more sensitive then the actual brake light switch. Just to be sure, I hopped into a RAV, Sienna, and Avalon also. The Avalon required a harder push on the pedal to activate the rear taillights. The Rav required almost no pressure at all. Doesn't sound like it is a "problem", just a weird anomoly. Just to be sure, when you bring it up for the oil change, I'll have my guy take a look at it to be safe.

 

I agree. The only other situation I can foresee is that tou were depressing the pedal, but were on a decline, thereby slowing you down more than normal. Again, these are just guesses from a less than qualified shadetree mechanic.

 

As I have posted before, while cruise canceling upon brake pedal use is normal, it is there for safety, not "normal use". Use the cruise stick - pull up. It's more "elegant", smoother, and more reliable. It's the way the cruise system is supposed to be operated.

 

Oh yeah.. a decline would cause you to speed up. Apparantly I was hit by the stupid stick early today

 

I just went out and duplicated this. By gently pushing the brake while cruise is engaged you can slow the car without canceling cruise. When you fully release the brake the car accelerates back to speed as it you would expect with cruise engaged.

 

My car is the same way, if you push gently you can have the brakes applied while the CC is trying to keep you up to speed. In the other thread (don't remember which one it is) I mentioned that I had taken my car in to have the brake activated CC cancel switch adjusted. I was told, as Jabber mentioned, that it is the same switch as the brake light switch. I was also told that if they adjusted it the brake lights might not turn off, I think that means they didn't want to fool with it.

I intend to adjust it myself when I get time, it's under the dash and activated by a tab on the brake pedal. Kind of hard to get to. By this time I have trained myself to cancel the CC with the CC stock and that works OK. But I think they should have used two switches so the brake lights and CC cancel could be independently adjusted.

 

I, like others, have just learned to pull back on the CC arm to cancel the CC since it just seemed easier and smoother.

After reading these posts, I tried to use the brake pedal to cancel the CC and found that I used about the same force that I have used in the past on my old Jeep and my wife's Honda Accord. I did not see much difference. I did not try pressing on the pedal lightly as you did.

I also tried to speed up and slow down using the CC arm. I was running 60 mph and pushed up on the arm until I was running 65 and released the arm. The CC overshot to 66 and then came back to 65. The same thing when I slowed to 60. This seems to work similar to my other cars, albeit the acceleration and deceleration was a little stronger than normal.

 

I was driving my new Prius for the first day yesterday with less than 110 miles on it when a cruise control problem startled me. I had been briefly using cruise control just before I was exiting the interstate. I tapped the brake and the car was slowing down as expected. Then suddendly it began accelerating on its own while I was coasting on the off ramp. I need to say the ramp was going uphill when this strange situation happened to me. The brakes easily got things under control again.

Since I barely use cruise control during my breakin period I've had no other chance to try to replicate this condition yet.

 

This is the way it's supposed to work on the Gen III Prius: light braking allows CC to continue. Heavy braking disables cruise. Pulling on the stick disables cruise.

Tom