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Cruise Control - threat or hazard?

Discussion in 'Gen 3 Prius Technical Discussion' started by bwilson4web, Feb 26, 2010.

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Prius cruise control - dangerous or hazard

Poll closed Mar 19, 2010.
  1. Have 2010 Prius - have a problem with cruise control.

    3.7%
  2. Have 2010 Prius - no problems with cruise control.

    65.9%
  3. Have 2004-09 Prius - have problem with cruise control.

    2.4%
  4. Have 2004-09 Prius - no problems with cruise control.

    25.6%
  5. Have 2001-03 Prius - have problem with cruise control.

    0 vote(s)
    0.0%
  6. Have 2001-03 Prius - no problems with cruise control.

    1.2%
  7. Do not have Prius - but Prius cruise control is dangerous.

    0 vote(s)
    0.0%
  8. Do not have Prius - no opinion about Prius cruise control

    0 vote(s)
    0.0%
  9. This is silly poll and I'm not going to play

    7.3%
Multiple votes are allowed.
  1. bwilson4web

    bwilson4web BMW i3 and Model 3

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    There has been one news article reporting a cruise control runaway several years go. But the first step in any fault isolation or diagnosis is to find original responders who may have additional details. One thing for sure, diagnosing a rumor wastes a lot of time.

    Bob Wilson
     
  2. fuzzy1

    fuzzy1 Senior Member

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    How about some choices for those of us who don't know because we rarely or never use it?
     
  3. paulemus

    paulemus New Member

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    I never had any problems with cruise control both in my Gen2 and Gen3. I wouldn't advise it in heavy traffic though.
     
  4. Susan4ET

    Susan4ET Member

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    I voted twice for 2010 Prius with CC no problem and for CC with problem: On the one hand it works fine with no unsafe condition/function noted so far. On the other hand it is much more responsive to increasing and decreasing speed then it was on my 2007 genII. I'm not use to this quicker response especially when increasing speed. I don't think this is a problem. I think it may waste gas though and wish the rate was adjustable? On the other hand, maybe I will use it a lot more and use the accelerator pedal a lot less? Does that make it more dangerous?
     
  5. spinkao

    spinkao New Member

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    Bob, I use CC in my 2008 very often and never had any problems, but from what I read over the Internet, I believe that the CC problem only plagued 2004 and 2005 models, and apparently was cured during the 2006 upgrade. I read a lot of stories about "runaway Prii", some even from creditable people, so I believe there actually *was* a problem - but all these problems I read of were isolated to 04-05 cars. I even remember one guy saying (don't remember where I saw it) that his problem disappeared after a visit to his dealer in 2006 for a regular maintenance - who knows, maybe they re-flashed some ECU firmware secretly?

    The fact is - if you look around for stories about Priuses gone wild, they are all from 2004 to 2006, and then they disappeared. I haven't seen any more recent reports. So maybe there was a firmware problem, but Toyota managed to fix it without public announcement, during regular maintenance visits of affected cars - that doesn't seem out of the realm of possibility to me.

    Anyway, I can testify that in my car it works exactly as expected, and is being used *very* often.
     
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    This is not a problem and doesn't really help us find anyone with a problem.

    Bob Wilson
     
  7. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Interesting! There may be a record of this in TIS. But this is consistent with the recent news report that mentioned at 2006 Prius.

    I made it a practice of staying away from the NHW20 forums. With a vehicle and manuals, I felt my comments would be more noise than help.

    Thanks!
    Bob Wilson
     
  8. Wiserone

    Wiserone Member

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    In my one day with my Prius, I did notice that there is a slight feeling of not being control when pressing the brake very lightly and in cruise control. I didnt panic or anything, but I wanted to lightly press the brake as the car in front of me was slowing down as it was going up a slight incline.

    I was pressing the brake very softly and then I heard the roar of the ICE and my car started to work harder to climb the hill and I held my speed even though I was pressing the brake. This was remedied in about .5 seconds and I just pressed the brake a little harder. I don't know if that qualifies as a problem, but I can certainly get used to just pressing the brake a tiny bit harder in order to disengage the CC.

    In my old Ford Focus I developed a routine of obsessively pushing the Cruise control off since the cruise control on button was messed up and would sometimes get engaged when I was hitting the horn.
     
  9. Joe166

    Joe166 New Member

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    I just don't understand what is dangerous and hard to adjust to about having to push the brake pedal an extra 1/4 of an inch?

    Yes, the Prius cruise control does not disengage as quickly as my last car did. It took one time for that to sink in and I didn't even remember it until I read the posts of despair.

    Not a problem. Have the dealer adjust the brake light switch if it bothers you that much. It is hardly a runaway car scenario, in my opinion.
     
  10. mitch672

    mitch672 Technology Geek

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    I love the DRCC on my 2010 V, I like how I can set it to 70-75, and if someone gets in front of me, it will slow sdown and adjust its speed downward, and then if they get out of the way, it speeds back up to it's set point.

    and I have had no issues with it either
     
  11. tumbleweed

    tumbleweed Senior Member

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    I voted No Problems, CC has worked as designed in both my '05 and the DRCC in my '10.

    But I do have the issue with the brake light/CC cancel switch being misadjusted. I do not consider it a safety issue and it can be readjusted, but the switch is a little hard to get to (at least for old guys like me). I plan to leave it until I have the brake ECU reflash done.

    I understand the concern over this because it does cause the engine and the brakes to interfere with each other until the CC finally lets go. This is quite noticeable when applying the brakes gradually and also means the brake lights are coming on a little late.

    I had my car to the dealer for this once but they didn't want to adjust the switch and I didn't feel like pressing the issue, I don't like to argue with them.
     
  12. bwilson4web

    bwilson4web BMW i3 and Model 3

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    This is why it is important to collect original reports. We've already gotten two, credible hypothesis:

    • 2004-06 intermittent problem - there may be a TIS that documents what happened to this early model. Reports suggest it might have been fixed as part of visits to a dealer service center.
    • 2010 Prius brake-light switch adjustment - there may some set that have a brake light switch that is a little late in coming on. This effect may be more or less pronounced with A0B but there is a random human element.
    I tend to turn off my cruise control manually or by shifting into "N", it also is disabled. Using my brake to disable cruise control is not something I've studied much but now it is on my list of 'things to do.' This doesn't mean there is a problem with my car but rather I don't know.

    This suggests very light braking might help us understand when the cruise control goes off. Doing it on an up-grade will ensure the engine is running and the transition should be easily identified.

    Thanks,
    Bob Wilson
     
  13. tumbleweed

    tumbleweed Senior Member

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    One reason some of us are accustomed to canceling the CC with the brake is because a lot of older vehicles did not have a separate cancel switch. In fact my '92 Chevy pickup has a factory CC and it has no cancel switch except for the ones operated by the brake and clutch pedals. If you don't want to use one of those you can turn it completely off with a switch on turn signal stock but then you lose the speed setting. So I expect most of us with those older GM vehicles just tap the brake pedal to cancel.
     
    1 person likes this.
  14. Joe166

    Joe166 New Member

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    You must be mistaken! I read on the internet (this forum) that everyone knows that the proper way to slow down from a cruise control ride is to pull the lever towards you. I must admit that this is the first car I have owned that worked that way, but obviously the guys who are smarter than we are have the world figured out according to them.

    Most of us who have had almost any car with cruise control just tap the brake pedal so that the speed settings are not lost. PERIOD!

    But I still don't think it is a hazard. I just don't understand freezing when a light brake pedal doesn't do anything. Push harder! Plenty of time to panic later. If you can't handle that, get a trike.
     
  15. austingreen

    austingreen Senior Member

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    I voted no problem, but I think I have the second problem. The brake switch to turn it off is not adjusted correctly with mine. I switched to turning off the cruise control with the stalk. No problem on runaway cruise control, but I used the brakes on my old car so that the light would signal the driver behind me. I have not tried since installing the software update. I do like signalling to traffic that I am slowing down.
     
  16. mad-dog-one

    mad-dog-one Prius Enthusiast

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    I have to bump the brake pedal a little harder in my 2010 Prius, compared to my other cars, but this slight difference does not represent a problem. I read a post on this site that the amount of pressure required to release the cruise control is adjustable, although mine is fine the way as it came from the dealer.
     
  17. Susan4ET

    Susan4ET Member

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    Hmmm... I drove another moderate trip today and now feel use to the slightly different feel/operation of the CC. I'm happy now with its operation and disengaging with the brake is no bother either.
     
  18. NovaStu

    NovaStu New Member

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    I totally agree. I absolutely love the DRCC on my car. It was worth every penny I paid for it. I'm so used to it that I [almost] take it for granted. Now I'm actually reticent about using the old-fashioned cruise control on our other car. In fact, my S.O. , after driving the Prius for a while, almost had an accident in the other car because the cruise control did NOT slow him down as he creeped up on a slower vehicle.

    Stu
     
  19. qbee42

    qbee42 My other car is a boat

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    Pulling the CC lever and tapping the brakes do exactly the same thing. Neither loses the speed settings, unless you slow down below the threshold speed. Below the threshold speed both lose the setting.

    I have owned several cars with CC. Each worked differently. It's up to the driver to learn how to best use a new car. Pulling the CC stalk to cancel CC is a nice addition to the system. You don't need to use it, but it's a lot slicker than flashing the brakes.

    Tom
     
  20. xvs

    xvs Member

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    My problem with the CC is that I am used to any tap of the brakes turning it off, and that is not the case with the Prius. I wish there was an option for that.