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Highlander Hybrid Brake Problems

124

Comments

  • wwestwwest Posts: 10,706
    "Normal" cars with ABS have no need to switch from regen braking ONLY into frictional braking ONLY if the ABS controlling ECU detects impending wheel lockup. And of course you would encounter this event more often in cold weather.
  • I own a 2006 Hilander Hybrid and it is a great vehicle except for the occassional brake problem that we all seem to experience. When I brake and have my foot firmly and gradually depressing the brake pedal, the car slows but there are these one second instances when the car continues to coast/lunge forward as if it is not going to stop. These short instances are terrifying because you begin to feel that the car is no longer under control.

    I find that it occurs at about 25-30 mph speed and I have observed it during colder days. No, it is not ice or wet roads, it is an inherent braking problem in the car that Toyota dealers and Toyota continue to deny or plead innocence.

    I suggest that you file a compalint with NHTSA at
    https://www-odi.nhtsa.dot.gov/ivoq/Complaint.cfm

    Make sure you use Hilander Hybrid in the vehicle selection. If we all register our complaints, hopefully NHTSA will be able to get Toyota address the brake problem with Hilander Hybrid too.
  • cdptrapcdptrap Posts: 485
    I believe several of us had filed this way back in 2006, I cannot recall now.

    To be clear, the "skip", "lurch" or "slip" has not in anyway shortened or threatened our stopping distance. After the first few instances during Winter of 2005 (bought ours in July 2005), wife and I learned to just be decisive, keep up the pressure and ignore the "lurch". We have stopped on ice, snow, slush, sand (Death Valley), road, dirt trails, rain and ranch/farm mud and muck without problems since we have owned this car.

    We have driven through the Sierras at various speeds and in various conditions from summer heat to winter snowfall with 6 or more inches on the ground. We have towed all the way through the Shasta range on HWY5 all the way from Redding into OR.

    We have also towed Brenderup horse trailer and utility bed trailer onto slick grasses and dirt roads without stopping problems.

    While we all dislike this "lurch", it is most likely not the same problem as the current brake-failure fiasco. Like WWest, I do not believe this is brake disengaging or not catching. I believe braking is continuing but it is the switch from regen to mechanical that is causing this "sensation". If anything, our "stopping problems" have all been related to lousy tires.

    Anyway, if Toyota would use software or some other means to fix this, I would really appreciate it. It certainly would boost my confidence in Toyota a bit. As it is, Toyota's long drawn-out denial after the CHP officer crash has really soured my trust in the company. Especially given we have many friends in CA law enforcement. For our next purchase, I will be looking at alternatives. Ford is a good choice now if it offers any solid and reliable larger hybrids. We will keep our HH until it dies.
  • I still think we all should file a complaint with NHTSA now, since the timing of the complaint will be right to urge NHTSA to direct Toyota to look into the Hilander Hybrid problem as well.

    If you think about it, Toyota could install accelerometers in some test vehicles, sample data from the brake, regen and the computer systems and analyze the data to evaluate the problem.

    Since several of us are complaining about brake problems in HH, this should not be such an elusive problem as some reports have suggested.
  • cdptrapcdptrap Posts: 485
    I am not disagreeing with filing at all, I think it is a good move. Was just being clear about our experience in this whole mess.
  • wwestwwest Posts: 10,706
    "...file a complaint.."

    And while you're there why not file a complaint about the ICE shutting down unexpectedly in certain situations. Hey, you bought a hybrid, now learn and understand, and live with, its idiosynchronies.

    I have little doubt that many owners felt this same way when they first encountered ABS activation...hey, something is wrong with my car, its acting funny when I go to stop.
  • 400e400e Posts: 41
    I think that the driver of a car has a right to expect that when he/she applies the brakes, there is a certain relationship between the pressure applied to the pedal and the stopping power of the braking system. When that relationship changes, in the midst of a braking episode, and does so unpredictably, that is just not right. I call it a design flaw, not an idiosyncrasy.
  • wwestwwest Posts: 10,706
    Are you describing ABS, VSC, BA, EBD or e/LSD......??

    All of the above fits..."does so unpredictably".
  • 400e400e Posts: 41
    I should have added the term, "frequently" to "unpredictably."

    In every other car I've owned with ABS and VSC (haven't had the other acronyms on prior cars), these features would kick in only very infrequently.

    On my HH, at least, the braking gap happens on a daily basis, but not consistently.
  • wwestwwest Posts: 10,706
    I wonder..

    With a FWD hybrid is it possible that the "gain" of the Anti-lock Braking System is increased as the climate grows colder..? ABS reacting much quicker to "impending wheel lockup" if the OAT is hovering near or around freezing...?

    An ounce of prevention is better than a pound of cure...??

    Regen braking applies ONLY to the front wheels, so if the rotation rate of those front wheels starts declining too far outside the "envelope", predictive target, ABS might disable regen as a pre-emptive measure.

    That certainly would account for your feeling that these events are more frequent with the HH vs non-hybirds.
  • cdptrapcdptrap Posts: 485
    edited February 2010
    I have never felt our non-hybrid ABS-equipped cars activating the ABS more frequently on cold days. This is true even after nights and days of low to mid 20's and driving in snow and slush. Our HiHy is the only one of our cars that does this "gap". Your hypothesis is very intriguing because my wife just made a surprising claim this morning.

    She said our HH "gap" frequency has dropped significantly since switching to snow tires. This "slip/gap/lurch" normally occurs right from the first cold-morning start. The first gap almost always happen as we coast down our steep driveway. Then twice or thrice more as we hit various stop signs and traffic lights before getting on the freeway. That was the pattern earlier this winter and every winter since 2005.

    Now, it rarely happens. I actually cannot remember it happening since we put on our snow tires.

    Could it be that All-Season hardens in cold weather and the car is detecting something that we cannot feel in normal driving? So ABS turns on sooner as you suggest?

    May be snow tires remain pliable and soft in low temperature so it is less likely to actuate the ABS?

    THis is just a wild guess right now. We will try to be more alert about this and report back if we have any concrete repeatable observations.
  • The fact is, mine is not a gap. Once the regen stops, it brakes via disk brakes only until the car is stopped. On the other hand, if I momentarily release the brakes and reapply, the regen + disk braking is back!

    Since some of us have slightly different symptoms, I would guess that we have slightlt different software updates..

    They should hire me! I could fix our wagons... Just kidding
  • wwestwwest Posts: 10,706
    edited February 2010
    "..I have never felt.."

    Again, a non-hybrid NEVER applies braking to ONLY the front wheels. In point of fact with a non-hybrid light braking results in more braking capability apportioned to the rear wheels than when moderate or heavy braking is being used.

    With a FWD hybrid using regen braking the front wheels, ONLY the front wheels. are being used for braking. Thus I would fully expect one of these hybrids to activate ABS's transition to frictional braking more often than a non-hybrid ABS standard activation, given equivalent conditions overall.
  • 400e400e Posts: 41
    Intriguing idea!

    In retrospect, certainly does seem to be a MUCH more common experience in my HH in cold weather compared to warm weather -

    Would the theory apply to 4WD HH's like mine? Seems like the same principle (i.e. a pre-emptive move from regen to friction when weather is cold) could apply - in other words, maybe the engineers figured that cold weather = higher likelihood of slippery surfaces, and so write the program to proactively get the brakes ready for ABS to run if needed.
  • 400e400e Posts: 41
    back to wwest's comments -

    your comment about "gain" made me think of that term in another way. The thing I find disconcerting about the "braking gap" is not the gap itself - it lasts maybe 0.5 sec or so - it's the fact that when the friction brakes kick in after the gap, the "gain" if you will is turned down and the driver has to hit the pedal harder to get the same braking effect.

    As I think about it, it would seem that it must be difficult for the engineers to perfectly match the two braking systems in terms of X amt of pedal force translates to Y amt of brake application. Perhaps they programmed the system so that when friction brakes kick in, they will, if anything, apply somewhat more "lightly" than regen? If they had biased the program the other way (friction > regen), the brakes would suddenly apply harder than intended and our cars would lurch to a sudden stop. Of the two outcomes, maybe they figured the former scenario was preferable?
  • wwestwwest Posts: 10,706
    "..the driver has to hit the brake harder..."

    Are you really sure about that...??

    Our natural, HARD to overcome, instinct when we feel that "lurch" forward is to immediately apply the brakes harder. Not that it would be easy, but have you ever tried just maintaining a constant brake pressure to see if the frictional brake, once that take effect, comes on at the same braking level...?

    Personally were I the design engineer writing the firmware specifications I would want the frictional brake to come online with even more braking ability than was just being used with regen.

    But then maybe that's what the new firmware "reflash" does.
  • wwestwwest Posts: 10,706
    "..the "gain" if you will is turned down..."

    Might that actually be a conditional situation based on the current, INSTANT, frictional coefficient of the brake pads themselves..?

    For instance the rotors being wet would undoubtedly result in having to press the brakes harder to get the same braking effect.

    Regen to frictional braking transition... not an easy firmware specification to write.

    Conundrum, for sure.
  • avucarguyavucarguy Posts: 56
    edited February 2010
    I agree with you. I have an 07 Prius with 62K miles. It does do the weird loss of braking once in a while, lasting less than a second, when hitting a bump while braking. This has never caused me any trouble. I think every one is so paranoid with the Toyota brake issues. Everyone is so focused on any small change on how the brakes on their Toyota behaves.
    If some of you are so worried about this "brake" problem, trade your Toyota in for another brand GM/Ford/ect. Don't stress yourselves out and get a heart attack or a stomach ulcer.
    As for myself, I will keep my Prius as long as possible to see how many miles I can put on it. Toyota and Honda are are the most reliable brands I ever owned in my 24 years of driving.
  • cdptrap: "I believe braking is continuing but it is the switch from regen to mechanical that is causing this "sensation"."

    I do not believe that braking is happening for that split second with my car. There is a definite increase in speed when it happens. Not a sensation. It goes like this:

    1. Apply brake at low speeds-Car slows down.
    2. Slippage occurs-Car coasts and speeds up.
    3. Brakes re-engage, car slows down and stops. Sometimes an abrupt stop to make up for increased stopping distance.

    I have noticed this on totally dry smooth roads. Bumpy roads. Wet roads, snowy roads, etc. All conditions and most times when ABS should not be needed.
  • wwestwwest Posts: 10,706
    "....split second..."

    Yes, probably the 100 milliseconds or so it takes to open the electrically operated solenoid that controls the ABS pressure porting manifold, and then another 100 milliseconds or so for the hyraulic pressure to "push" the brake pads into firm contact with the brake rotor.

    "......ABS should not be needed..."

    And if you weren't driving a FWD hybrid most likely "ABS" wouldn't be needed. I would imagine that during regen ONLY braking the ABS's ECU might be more sensitive, higher "gain", to the slowing of a braking wheel. Maybe even moreso, incrementally higher gain as putside temperature falls near freezing level.

    The easier, quicker, regen braking slows the wheel(s) the more important it becomes to switch braking modes. A slight bump in the roadbed, slippery crosswalk stripping, a railway rail, anything that results in a braking wheel momentarily losing contact with the roadbed, and regen gets instantly cancelled.

    What you are feeling is most likely NOT actual ABS activation, but the "switch" to a braking mode that CAN be controlled via the anti-lock system should the need arise.
  • I appreciate that you're a Toyota fan. My '06 Highlander Hybrid has also been among my favorites. However, I have been disappointed that since '06, when I first reported the problem to Toyota, they have been unresponsive and denied that the problem existed. I'm one who doesn't complain and wasn't looking for a lawsuit. And, no, I didn't know anything about all the other problems that are now surfacing regarding hybrid braking. What I do know is that my vehicle occasionally experiences a "gap" in braking friction during a forced transition from regin braking and stops further than anticipated. I bumped the car in front of me the first time I experienced the problem and not expecting it. It could have been a person at a crosswalk. That's not paranoia - it's a legitimate concern. If there is a software fix, then all of us should get it! Though we shouldn't have to pay for it, I would buy it.
  • Yes I experienced that effect over a dozen times with my car. I just traded it in last week. It was a 2006 Highlander Hybrid. It would surge/accelerate for 1-2 seconds unexpectedly when applying the brake. About a year ago, this defect issue also started to include the cruise control...when I would brake when on cruise, it would do the same. I had taken it to the dealer twice and they ran diagnostics and didn't get to witness the defect. It came back "'no codes stored'. You will want to watch ABC's World News Tonight video on how it could be caused by an electronic componet and displayed as such. It also shows the same code when ran through diagnostics. There are also 8 reports on NHTSA's website for 2006 Highlanders having the same/similar issues and a couple which ended in crashes, with one driver being faulted for accelerating, which I believe was caused by the defect, not the driver. After reading those and still going through unexpected surge/acceleration encounters, I felt it was best for me to own a different vehicle. I no longer felt safe driving it, which is unfortunate, because I really liked my car other than this issue. I don't believe this issue is at all normal, but the dealer may tell you different. The dealer here thought my car was safe to drive, however he had no idea how he would feel if it was his car or any one he particularly cared deeply about being in a car with the potential to injure/disable or kill those in the car or another vehicle. Hmmm...?
  • Mine would happen unexpectedly and either immediately upon braking or after a few seconds of slowing down. Check out the NHTSA's website and ABC's World News Tonight concerning electronic system in Toyota with theory proven.
  • The dealer I went to denied there was an issue and said "it was safe". And yet, we are seeing something different.
  • bryankmbryankm Posts: 4
    edited June 2010
    I just found this thread last night and I wish I saw it earlier because that braking flaw finally caught up with me and there was nothing I could do but crash.

    Here's what happened:

    I was traveling home from business and was heading northbound on NY State Thruway 87 with traffic more to the heavy side but moving smoothly, weather conditions were excellent. Well apparently a goat had wandered onto the Thruway and a tractor trailer driver locked up the brakes to stop for it. The few cars between myself and the tractor trailer quickly moved over to the left lane with the last one swerving almost at the last second. I moved my foot over to the brake seeing that there was probably slow moving traffic ahead and when I saw the truck, it didn't have brake lights or flashers on so it took me a moment to process that he was standing still. Well I had to make a quick decision: the left lane was blocked for me because everyone else had swerved to it, the right shoulder had a guard rail from the underpass I had just went under; I thought I could try to get through the small gap between the truck and the guard rail but I thought I might flip if I hit the rail too hard so I chose to square up on the truck's bumper and stood on the brake pedal and that was at about 90 to 100 yards till impact. Well the anti-locks started out well and I felt 5 to 10 pulses of the brake then (just as all of you have described and we all know happens with this vehicle) the brakes stop and the vehicle is coasting but doing it at 50+mph. The Highlander continues coasting for 40+ yards (1 to 2 seconds as I recall) before the anti-locks start working again but at this time it was too late and I hit the tractor trailers rear bumper at about 50mph and stopped dead (the bumper on the trailer was too high for the Highlander's frame so the bulk of the deceleration occurred at the motor and passenger compartment, 50mph to 0 in about 3 or 4 inches.) The collision guys couldn't believe I walked away from the accident, they told me that 'high hits' at that speed against tractor trailers are almost always deaths or paralysis at best. I am messed up for sure, hands and feet are numb and back and neck are incredibly painful. I have bruises that run from my ankle right up to my knee from the dash board and my right knee split open also from the dash. I had a large goose egg on the crown of my head from where the high hit of the trucks bumper drove the vehicle down. All in all, I shouldn't be here writing this post but could easily be in a funeral home somewhere waiting from my family to have me buried.

    I called Toyota several times about this and no one has ever called me back. Last year, after the Prius recall, I wrote an email to the US Department of Transportation telling them that the Toyota 2007 Highlander Hybrid has the very same failure mode (I.e., brakes not functioning consistently during rough driving conditions.)

    Reading through the previous posts here, my vehicle did the exact same thing as the rest of yours does. I know of at least three failure modes on my Highlander Hybrid and they have been described here previously but here they are as I know them: 1) the low speed surge while the regenerative braking system switches to friction braking, 2) stopping on slippery roads especially ice and slush, the anti-lock brakes stop functioning and don't work again till the vehicle is almost at rest 3) under rough driving conditions the brakes will stop working for 1 to 2 seconds before re-engaging ... which was the one that resulted in such a bad collision for me.

    My advice to those of you who still have Highlander Hybrids is don't except any excuses from Toyota or the dealership. This is Toyota not doing the right thing because I'm sure they are aware of the problem. I had learned to live with the failure modes in the braking system like the rest of you have but one day you might be faced with the same situation as I just was and have to watch a stationary object (like a tractor trailer) come at you like a freight train and know there is nothing you can do about it.

    I'll try to post pictures if I can ... pretty nasty looking I can tell you.
  • paracletosparacletos Posts: 12
    I have not been watching posts for several months, but this is the first I've heard of this problem happening at high speed. Sorry for what has happened here, and thankful you're ok. This post merited a response from me because, for the first time I noticed the "gap" in braking friction after hitting a bump on the Xway recently. I had hoped this was only a low speed problem but now am concerned since I was traveling at about 60mph. It has not been my sense that all braking disappears momentarily - but rather a significant reduction in braking friction, which definitely increases the rate of closure on a stationary object. Did your brakes seem to fail altogether or was it more as I have described?
  • bryankmbryankm Posts: 4
    Paracletos, They failed all together; there was no braking for as described above about 1 to 2 seconds. I never did have it happen at a speed higher than 45 mph before but I don't have to stop quickly from high speeds too often so maybe it was just a combination of factors coming together at once and probability.
  • Kirstie_HKirstie_H Posts: 10,918
    Holy smokes!! I don't think I've ever seen a car damaged that badly, with the driver walking away relatively intact. Really glad that you at least made it out alive. Those are amazing.

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  • paracletosparacletos Posts: 12
    If there is anything good to say about Toyota in this situation it is that the SUV stood up to an enormous collision with the passenger compartment remaining intact. Of course there's the bad part - where the brakes contributed to the problem. The ugly? That's what remains of the Highlander! Glad the driver is OK.
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