1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Brake lights light up late

Discussion in 'Gen 3 Prius Technical Discussion' started by Natedogg, Jan 16, 2010.

  1. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    Well, you guys aren't alone - I've independently come to the same conclusion, with the exact same symptoms. I've also crawled under and peered up. It looks like the switch has an external thread and a jack nut. Of course, it's all plastic, so I'll bet care should be taken.

    I also believe that the dealer SHOULD be responsible for this adjustment, but anticipate hearing the "Its just fine" from them.

    My only concern is: In a "normal" car, I'd proceed to adjust the switch without hesitation - but in our hybrid - are these odd symptoms which clearly indicate a need for adjustment - intentionally designed?? Is there some other purpose? (Not that I can think of one - but I'll bet the designers are more thorough engineers than I).

    Anyone else think of a reason we couldn't/shouldn't make this adjustment?

    Edit: The Cruise Control thread referenced earlier includes directions on how to make the adjustment. Take a peek over there. Overall, It's easy-peasy. Although, it'd be a tiny bit easier with a third arm/hand. Note the brown plastic nut that looks like a jam nut is fixed. The only thing that turns is the green switch housing. Those aren't external threads - they are a plurality of different engagement points - adjustment levels.

    I just hope this doesn't miscalibrate the flux capacitor.
     
  2. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    Yes thanks to Bryce04 in the http://priuschat.com/forums/gen-iii...m/69870-releasing-cruise-control-brake-6.html thread I did mine also. No problems and now it works as it should. The brown plastic nut looking thing is fixed as you pointed out (I would have tried to turn it!), we just turn the green switch CCW 90 degrees to unlock it and move it up or down then relock it.

    So why don't dealers want to do this? Is there some kind of war going on between dealers and Toyota that we (customers) are caught in the middle of? I sure hope not.

    Don't worry about the flux capacitor, it is only miscalibrated when you turn the reverse beeper off.
     
  3. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    Uh-oh - I did have the dealer turn that damn reverse beep off.

    I haven't tried to mention the brake switch position - I only just realized it today, as I was trying to disengage cruise, and I could feel the engine fighting me. Then, I noticed it took quite a bit of pedal depression to get the light to come on.

    I think, overall, the dealer service writers are hesitant to second-guess factory, even when the evidence is clear to them. Take the present environment into consideration, and their perspective isn't too mysterious... Nonetheless, they should listen to their customers.

    I'm still hoping that there isn't some specific reason for this. I definitely want my brake lights coming on sooner rather than later...
     
  4. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    I think you are right about the dealers. I was just looking to start a good conspiracy theory. :)

    I took my car for a long drive and turned the CC on and off, canceled with brake etc. no problems. Based on the CC schematics that were posted on another thread I think we have nothing to worry about.
     
  5. Susan4ET

    Susan4ET Member

    Joined:
    May 9, 2007
    429
    52
    0
    Location:
    Central Oregon
    Vehicle:
    2015 Prius
    Model:
    Three
    This will become an issue if there is no adjustment. If you are applying your brakes the lights need to come on and the CC needs to disengage too at the same time. So you all should go back to your dealers and Toyota Customer Support and and get them busy on these issues before we have another recall. So far I'm not noticing either problem. I'll bet almost anything that the brake pedal switch is adjustable...or defective in some way--especially if this is some situation that is growing worse (more delay where there was little if any originally).
     
  6. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    it is adjustable. So noted 3 posts up in this thread, and also in the referenced CC thread.

    We probably should have dealers do it - but good luck with that...
     
  7. Jim05

    Jim05 Occasional Quasi-Hypermiler

    Joined:
    Aug 22, 2009
    115
    20
    0
    Location:
    Culpeper
    Vehicle:
    2010 Prius
    Model:
    IV
    At last, my dealer adjusted my brake pedal switch!! :cheer2:
    It comes on at about 1/4 inch (0.6 cm for those metric folks) depression and deactivates the cruise control, etc. It's so nice being able to use my brake pedal/lights as a warning to folks behind me instead of creating an emergency for them. And to think, it only took 3 trips to the dealer and 2 phone calls to Toyota Customer Service to get brake lights working properly :eek:.
     
    1 person likes this.
  8. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    I took mine in also and they said it didn't need adjustment, but they did enter the trip on my service record so Toyota is aware I ask to have it fixed. It' been over a week and about 300 miles since I adjusted mine and I am happy with it.

    One thing to be aware of, this switch seems to have a third function in addition to CC cancel and brake lights. It is used to determine when you are allowed to start the car (put it in Ready) or shift in or out of Park or Reverse. I don't think this is a problem but maybe the driver should know about it.
     
  9. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    One question burning in my mind - and I think I've been experiencing some placebo effect: Does this have any effect with regard to regenerative vs friction braking?

    For example: you can have extra regen braking before the switch is closed (lights come on) - but that once the lights come on - at least some friction braking comes into the mix?

    I don't think so - but I'm always afraid of unintended consequences to my actions... :)

    (I've already adjusted mine, and am overall quite happy).
     
  10. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    No effect at all on that function (regen vs friction). The only difference you will notice while driving the car is that the CC will cancel sooner and maybe people behind you will realize you are braking sooner than they would have.
     
  11. pakitt

    pakitt Senior Member

    Joined:
    Aug 10, 2009
    2,173
    1,311
    0
    Location:
    Colorado
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    Guys, I don't know what you are talking about - really. I tried today checking when the lights come on on my Prius 3rd gen and they come on exactly when I expect them to. The first cm or so nothing happens, and rightly so - if you put your foot on ready to brake, but you really don't want yet, the lights should not come on. They have to when you do want to brake.
    I believe the lights come on exactly as on the Polo I used to drive. And moreover, I am pretty sure that if the lights were not coming up early enough, the EU would not have allowed the sale of the car in the EU. My brake lights turn on pretty much alright.
    Why are you finding problems where there are none?
    If it really happens that they turn on after a quarter way down, then there is an issue, but then I don't see how a dealer would deny that to be a problem. A quarter way down is way more than 1 cm.
     
  12. Fuel Miser

    Fuel Miser Junior Member

    Joined:
    Feb 19, 2010
    86
    22
    0
    Location:
    Ontario, Canada
    Vehicle:
    2010 Prius
    Model:
    N/A
    Huh! I discovered this only by reading it here.

    I went out and ran some road tests on my street with a reflective sign behind me. As I was modulating the brake pressure just prior to coming to a stop... about the last few car lengths of coasting... my brake lights went out! SON OF A..:censored: ... thats just a tad too dangerous for my liking.

    So without tools, just my hand and a flashlight, I reached up and grabbed the actual switch mechanism where it plugs in, and gave it a gentle twist. TaaDaaa! it turned pretty easy. Took me a couple of adjustments, but now it comes on when expected, and doesn't go out until I really let go of the brake. I figure it has about 1cm or so of free travel now, instead of the near 3cm it had.

    5min work to prevent from being rear ended. Priceless. Thank you Prius Chat !!!
     
  13. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    Then why bother to post? Clearly you don't have the problem.

    Clearly we do. I'm a registered professional engineer who began my career working for an automotive supplier. All parts have tolerances. Some, like our brake light switches, are intentionally adjustable to allow for the very adjustments we have found necessary and have made (either ourselves, or by our dealers). Just because yours is in proper adjustment does Not mean that our were. (They are now).

    There are lots of problems that others have that I don't - that's the nature of manufacturing - observing the effects of tolerance stacks.

    You have added no value to this post whatsoever.

    Carry on...
     
    1 person likes this.
  14. eestlane

    eestlane Member

    Joined:
    Sep 29, 2007
    110
    11
    0
    Location:
    Space Coast, FL
    Vehicle:
    2007 Prius
    I second the motion!
     
  15. pakitt

    pakitt Senior Member

    Joined:
    Aug 10, 2009
    2,173
    1,311
    0
    Location:
    Colorado
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    I don't - the fact that this does not get repaired/adjusted at Toyota Repair shops, means to me that it is really not a problem, it is according to specification and not to your liking.
    The end result is that, especially in this Toyota bashing climate, readers on PC reads this and think, oh God, another one, the brake lights are not turning on - I will get rear-ended.
    Someone in one post even went all the way to say that its Prius is "not safe anymore".

    If the pedal distance to turn the light on is not according to spec, then why the dealers are not fixing it? because maybe it is really not a problem???! and it is in fact according to spec?
    Either the switch is moving around, which means that sooner or later the switch will move again, otherwise the switch does not move and you were used with very sensitive brake pedals with switches turning on the brake light at the slightest pressure of the pedal.

    But this goes a long way before saying that the Prius is unsafe.
     
  16. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    The service department I visited didn't mention anything about a specification, to them it either works or it doesn't. Mine worked, i.e. if you push down far enough the brake light comes on, so they didn't adjust it. There may be some kind of spec but I don't have a complete service manual so I can't check.

    One of the problems is the use of a single switch to operate 3 separate functions. The brake light, the CC cancel, and the interlock for the "Ready" mode and shift selector. But if it is adjusted to far down for the interlock, as several of us have discovered, the brake light comes on way to late and the engine starts to bog down before the CC is canceled. I'm sure that's not what Toyota intended. Why dealers are reluctant to adjust it is unknown to me.

    This is not a case of the adjustment moving after it has been set at the factory. The way this adjustment is designed that is not going to happen. It's not like a screw that you can loosen or tighten and set anywhere in between. It is a big switch that turns 90 degrees to unlock and can be moved up or down to one of several different notches then turned 90 degrees to relock. It just can't unlock itself, move, then relock itself. To lock or unlock it you have apply quite a bit of pressure and it kind of clicks over.

    Inasmuch as the switch is well designed and isn't going to move by itself, some of them left the factory adjusted wrong. That kind of thing happens, especially with new models and workers that are not familiar with the procedures yet.

    This is not unique to the brake/CC switch. My headlights were adjusted wrong also, aimed so low that I could overdrive them at 30 or 35 MPH. Others with earlier cars and LED headlights had the same problem, fortunately the headlights are easy to adjust. Dealers seems reluctant to adjust them though. It almost seems that the service departments are under the impression that every thing that leaves the factory is perfect and they shouldn't touch it, that philosophy fits right in with their "customer is always wrong" policy. :)

    Some people might actually think that not having brake lights come on when you push the brake down far enough to stop the car is a minor safety issue? In my car I knew the CC cancel was adjusted wrong the first time I tried it, but I did not know the brake lights used that same switch. I remember wondering why some people seemed to be trying to drive into my back seat when I was braking!
     
  17. pakitt

    pakitt Senior Member

    Joined:
    Aug 10, 2009
    2,173
    1,311
    0
    Location:
    Colorado
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    No, actually is called "WE know better" approach. Where "We" does not stand for "customer".
    It is very, *very* common in Germany. This is why germans often go wrong, you tell them it's wrong, they continue, then they bang their head, *hard*, on the wall and then they listen and start really doing something about it. Usually they come out better from the experience, but still the "We know better" approach remains.
    Japanese, I must say, are similar in a way. The customer is always right, but doesn't understand a thing - it is just a user.
    :D

    Thanks for your post, BTW - one that says a bit more clearly the facts and doesn't go around saying that the car is not safe, that it will kill my wife and kids (and why not, the driver himself), and that you will sue Toyota for it.
    (This has been the trend lately also on PC, I'm afraid).
    I am not saying that the switch is perfect out of fab, but it goes a long way before saying that the car is not safe, that there is a PROBLEM and so on - as I have read in this thread here and there.
     
  18. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    This was described well in this thread and it's sister-thread about cruise control. If you have something valuable to add. Go ahead. If not, feel free to remain silent.
     
  19. pakitt

    pakitt Senior Member

    Joined:
    Aug 10, 2009
    2,173
    1,311
    0
    Location:
    Colorado
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    I am not going to remain silent as long as people claim the car is not safe based on impressions and not facts. I surely have had something more valuable to add by confronting the statement that the brake light was not coming up as "expected", than those in this thread claiming with no reason whatsoever (ie. fact!) that the car is "unsafe".
     
  20. eric1234

    eric1234 Active Member

    Joined:
    Jun 8, 2008
    390
    198
    0
    Location:
    Hamden, CT
    Vehicle:
    2016 Prius
    Model:
    Three
    Your earlier quote says it all:

    "Guys, I don't know what you are talking about - really."

    The cruise control thread describes more than one driver who have experienced braking deceleration with continued engine torque delivery. Are you suggesting that this is normal? Many of us have owned many vehicles with Cruise Control. Based on the reported experiences of others and myself, brake deceleration and engine torque are never simultaneously delivered under normal circumstances.

    Because the cruise cut off function is shared with the brake light function - this is indication that braking force is delivered before the brake lights are applied. What is the function of the brake light? It is to signal to others that the car had begun deceleration. Brake lights are an inherent safety function. If they are applied after braking is begun, it most certainly is unsafe.

    Is it as unsafe as the alleged UA? No, of course not. No one has said it is.

    Therefore, you are not adding anything other than your own conjecture, based solely on your own admitted ignorance.

    Do us all a favor. Keep your ignorance to yourself.