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Prius 2001, brake light on and car slow down

Discussion in 'Newbie Forum' started by try4141, Jul 1, 2010.

  1. try4141

    try4141 Junior Member

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    Hi All,
    My Prius 2001 with 140k. Sometimes while I am driving, the brake light aumatically comes on and the car slow down by itselt. I have to stop the car, turn the engine off, then turn it on, then the brake light is gone and the car would run as normal. It happen less often before, like 2 months ago, but now it happens more regularly, say every 10-15 miles. Did not have the chance to read the code. What could be wrong? ABS, rear brake, regenerative sysytem, transaxle?
    Thanks
     
  2. tumbleweed

    tumbleweed Senior Member

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    Assuming the Gen1 Prius is the same as the other two models, the brake light is activated by a switch under the dash that is contacted by the brake pedal. But the brake light coming on would not cause the car to slow down unless you were using the cruise control? that same switch also deactivates the cruise control. But that shouldn't require restarting the car.

    So I guess you are going to need to provide more information before we can make a guess, unless someone else has had the same problem.
     
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  3. jdcollins5

    jdcollins5 Senior Member

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    Another question for clarity, are you talking about the brake lights on the back of the car or the brake icon on the dash ?
     
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  4. try4141

    try4141 Junior Member

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    Hi all,
    For clarity, the brake light on the dash board is the one that is ON, NOT the brake light by the bumper. There is nothing wrong with the switch at the parking brake. When I was driving at 50mph, all the sudden I felt like the car is stopping and the brake light in on, after that the car will slow down. The car still can run but sounded very heavy, just like we are driving with the parking brake on. I have to stop the car, turn the engine off, then on again. Then the car can run normally. But the same thing would happen again after 15-20 miles or so.
    Thanks
     
  5. tumbleweed

    tumbleweed Senior Member

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    OK, that clears it up a bit, I thought you were referring tho the stop lights in the back. With out looking at the codes it would be hard to make even an informed guess, braking ECU perhaps.

    I would suggest you read out the codes and repost your problem in the Gen I Prius Discussion forum: Generation 1 Prius Discussion - PriusChat Forums
     
  6. Reza75

    Reza75 New Member

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    Hi I have the same problem .did you find out what the problem is?please let me know if you know what's wrong and what could be the problem.thanks
     
  7. Reza75

    Reza75 New Member

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    Hi I have the same problem .did you find out what the problem is?please let me know if you know what's wrong and what could be the problem.thanks
     
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  8. KDEN

    KDEN New Member

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  9. twittel

    twittel Senior Member

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    Well, someone has to take the initiative to get their car to the dealer; if no other reason then to get an estimate. If the brake light on the dash is lit, you're looking at potentially everything connnected to the brake system starting with the master brake cylinder to a shorted wiring harness. Hope y'all find some answers here at PC, but the dealer would be my first stop.

    Happy Motoring,

    Tom
     
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  10. twittel

    twittel Senior Member

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    Ooops, I see this is an old thread. I'm sure all is resolved by now.

    Happy Motoring,

    Tom
     
  11. try4141

    try4141 Junior Member

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    Sorry for late reply. I fixed the problem by changing 4 bad cells in the traction battery. Hope this helps.
     
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  12. PriusVT

    PriusVT Junior Member

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    Hello, did anyone come up with a fix for the problem of the brake light (the dashboard indicator light-not the brake lights on the rear of the car) coming on while driving at highway speeds and engine sounding like it is revving? My 2001 Prius with 180K just started doing this. To get the problem to “go away†I have to stop the car, turn it off and then restart it. The car then runs normally but the problem reoccurs. I’ve noticed that the cruise control is no longer functioning. Also one of the cells in the battery is failing. Are these issues connected?
     
  13. seilerts

    seilerts Battery Curmudgeon

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    If you have a problem with the HV battery, then you have a problem with regenerative braking, which will turn on the brake light.

    There is lots of information here on fixing your battery yourself, if you feel so inclined.
     
  14. Knrruler

    Knrruler New Member

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    May i know how to repair battery ourself
    Thank you
     
  15. Marc Pierre

    Marc Pierre New Member

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    Please give me details on how to go about fixing the car as you did, thanks
     
  16. Marc Pierre

    Marc Pierre New Member

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    And how much did it cost you.
     
  17. RCO

    RCO Senior Member

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    Sorry to rain on your parade Marc, but the OP was last seen on this site almost 4½ years ago!

    Since he's not been back, in not sure if a poke @try4141 will work. It seems not to be recognized, so unless our esteemed moderator @Tideland Prius can help contact him, you're out of luck my friend.