Cruise Control - threat or hazard?

I had the same problem. Bob is correct, as usual, the brake light switch which also cancels the CC probably need adjustment. Bryce04 has posted instructions for that adjustment in post #55 of http://priuschat.com/forums/gen-iii...m/69870-releasing-cruise-control-brake-6.html I adjusted mine this afternoon and my CC cancels with just a tap of the brake pedal now. Easy to do.

Hint: the brown plastic nut looking thing doesn't turn, just turn the green switch 90 degrees CCW to unlock it, then pull it up just a little to adjust and turn it back CW to relock.

 

Just do not use the brake to disengage the CC .... use the CC stalk;it is an immediate disconnect that way.

 

So you retain the speed setting on these older cars when you disconnect the CC using the brake?

 

If you are in traffic like that you should not have the car on CC. Cruise Control is for exactly that .... cruising at a set speed in very light or sparse traffic conditions.

 

Agree totally. Learn the car features and use them appropriately.

 

Yes you do, and it's the only way you can. The other choice is to turn the CC completely off.

Now that we know how to adjust the switch on the Gen3 it's not a problem anymore either. I did mine this afternoon and now I can cancel it the same way I did my Gen2 and every other car I have owned that had CC.

 

Aggressive resume causing unexpected unintended acceleration: This is something I have experienced maybe a dozen times in 30 years with different vehicles. Here's what happens, your cruising at 70mph and you have to slow down for say a construction zone. You tap the brake and coast down to say 45mph. You then proceed under foot control until clear of the zone. You hit the resume button and your car just launches, lots of throttle tranny downshifts and then your hard on the brake to keep from hitting the guy in front. I can't be the only one to have this happen.

So what is the 45mph to 70mph time in your car any brand any model using CC resume?
How do the different power settings for the Prius effect this?

 

I think that falls into the same category of sneezing when the car in front hits the brakes. There is no real cure, but to answer your questions.

ECO mode accelerates slowly. So much so that it loses some speed on hills, and has large delays when I tell it to speed up a couple of mph. It will catch up on flats and downhills. To me this is irritating enough for me to switch to power mode when I'm using cruise control. This maintains speed more as I expect it.

My previus car was a lexus gs with 300hp. Resume would make it accellerate quickly. I never hit resume from a low speed in traffic, I would accellerate manually to close to the right speed, then hit it. I still prefer this method in the prius.

I do use the cruise control in situations I would not previously. I have a hard time sticking to a set speed with this accelerator, so I use the cruise and the 1 mph increments. The car and driver review of the fussion mentioned that it had the same issue. So with the cruise, I don't have to worry that much about the accelerator feel.

 

I have the 2010 with radar CC and voted no problems, just taken time to get used to all the new features.

Differences to previous Toyota Kluger (Highlander) are
Radar of course
Cancel gets used more as brake pedal not as useful to me.
After using brake it retains the setting and it can be reset.
The holding up or down steps the speed in 5 kph steps - easy to set on entering and leaving towns on highway.
System actively brakes to bring speed down to setting rather than waiting for car to coast down to speed - holds speed accurately even down quite steep hills.
Sensitivity seems to be affected by Eco/Normal/Power mode to some slight amount but on our recent long trip made very little difference to fuel economy.
Radar distance keeping is fantastic, even tend to use it in traffic travelling at 60 kph upwards and speeding fines much reduced.

Paula has driven one 2 hour stint on the Hume Highway using it and is taking a little longer to adapt to new features.

David

 

You can cancel the cruise control without removing the set speed by pulling the lever towards you, then you can resume to the set speed by pushing the lever up (I think). rtfm.

There's no need to use the brakes unless you really need to brake.

Edit: Ooops, I had not noticed that you were talking about older cars, my bad.

 

I fooled around with power modes a little when I first got the car, now I use ECO all the time. But what I remember is the power mode only effects the input from the throttle pedal, inputs from the CC are the same in any of the three modes, ECO, Normal, or PWR. I don't use resume to get back up to speed very much because it is just to aggressive, I usually just drive up to within 2 or 3 MPH of where it is set and then hit resume.

 

I've wondered about this too. Is it possible though that returning to speed more aggressively might save you mpg more then returning to speed more slowly over a longer time period?

 

Yes I think so, but maybe with not quite as much throttle as the CC applies? I have no data to back that up it's just a guess based on what I read about driving for fuel economy. I think accelerating very slowly is not good, and full throttle is not good, but where in between is best? Probably varies between types of cars and maybe even with temperature, up or down hill, etc.

Maybe one of the good engineers on this site will devise a test.

 

I have a 2004 with 125k miles, and use the cruise control extensively on long highway trips. I generally disengage it by pulling stick control, but brake application also works all the time.

I use the speed up/down 1mph per bump up/down feature often and it's always worked great. Not sure why Woz had an issue with it?

I just got 2010 and so far the cruise control seems similar, and no problems at all.

Thanks, John

 

My guess is that he was driving a V and using the DRCC which is the default (you can select normal CC). With the DRCC if you just tap the lever up or down it increments or decrements the speed by 1 MPH per tap, just like the normal CC. But if you push it up or down and hold it for a second it increments or decrements by 5 MPH vs 1 MPH, and it keeps doing it. So if you have it set for 40 MPH and hold it up for 4 seconds it will be set for 60 and you will accelerate fairly briskly. If you are going 60 and hold it down for 6 seconds it will be reset to 30 and use the brakes to slow you down fairly quickly.

So Woz probably doesn't read owner's manuals and was surprised by what it did. When I took delivery of mine no one told me about that feature because the dealership had never even seen a V with ATP before. Fortunately I do read owner's manuals.

 

I have been following this thread and others about the aggressiveness of the CC. My thoughts on this are that the way CC works is that the greater the difference between the speed setpoint and the actual speed, the greater the aggressiveness. If it did not work this way, it would have difficulty maintaining speeds going up and down hills, etc. Then there would be others complaining about the slow response and lack of ability to maintain speed.

Also, I thought back to my past vehicles with ICE only and auto transmissions. What happened with these when you started up a steep hill? It would downshift to a lower gear and really accelerate. I do not think the Prius is any more aggressive than my past vehicles and maybe a little less since it does not have gears.

My apologies for getting off track from the OP.

 

I’ve had my 2010 Prius for two months with no problems except you have to tap the brakes hard to disengage,
BUT THEN LAST WEEK!!
I was driving to work using my CC like I always do, set at 60mph then suddenly it speeds up to 68mph, and stayed there, until I hit the brakes, freaked me out a bit I was ready to hit the off button. Road was level, no mats in the way and my feet were not touching the pedals! what made it worse was the previous day on the radio they had the 911 call of the San Diego family who died in their Lexis.