Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!





Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Highlander Hybrid Brake Problems

PF_FlyerPF_Flyer Pennsylvania Furnace, PAPosts: 9,403
Having an issue with the brakes on your Highlander Hybrid? This is the place to work out a solution!
«13

Comments

  • poodlgalpoodlgal Posts: 13
    I am noticing a little "gap" in the brakes when I am slowing down and just as the ICE kicks off. It is as if the brakes let up for just a second (the car surges slightly as if I had taken my foot off the brake) - and then the brakes kick in again. It's a bit disconcerting! Has anyone else noticed this? I'll be checking with the dealer at my next visit, but wanted feedback from the group as to whether this is "normal" or an acknowledged problem. I don't remember this happening when I first got the car; I've had it 6 months now. Thanks for your advice/opinions!
  • cdptrapcdptrap Posts: 485
    We are experiencing this as well but randomly, not consistent and not often. Do you experience it consistent enough to notice a pattern? If you do, can you please share?

    Will be checking with dealer's shop as well in a week.

    Ours seems to occur when applying the brakes after coasting. As we step on the brake for the final stop, there is a slight surge (gap) and then the brakes take hold. It does not happen all the time.

    I wonder if it has anything to do with the car switching from "recharge-induced slowing" to actual braking.
  • nomorebenznomorebenz Posts: 109
    You're onto something there. I have noticed it on mine. May have something to do with the ISC (Idle Speed Controller). When you are close to stopping, the power flow switches direction and goes back to the wheels (to simulate ICE idle). This could be contributing the surge. Let's see what others have to say.
  • mmreidmmreid Posts: 88
    I've noticed this "surge" only a few times when I've been coasting towards a light or stop sign and the car seems to hit a slight bump in the road - but only when it hits a bump or other obstacle like a tiny pothole. I wondered what it was - felt like the car wasn't braking for maybe half a second and almost like it jumps slightly and then the brakes work just fine. I wondered if it was me or what. . .should we talk to Toyota about this? Is it a safety issue?

    mmreid :confuse:
  • katzjamrkatzjamr Posts: 146
    the 'surge' is normal as the regenerative braking adjusts depending on the amount of charge needed for the battery.
  • poodlgalpoodlgal Posts: 13
    This may be "normal" but it is disconcerting at the least, and seems like it could be dangerous. Yes, it occurs most often after I have been coasting (like stopping as I am coming to the bottom of a hill). Sometimes the surge or "brake gap" puts me a little further forward than I want to be - and in the case where I might be stopping in an emergency, might put me in the intersection or on someone else's bumper. If anyone learns more from their dealer/mechanic about a possible fix, please post it!
  • newski3newski3 Posts: 42
    I just returned from an 88 mile round trip to a small town up the road using paved 2 lane roads with little traffic. Two things:

    First, as I was returning home, I was descending a l-o-n-g downhill grade ;;; ah, regeneration time ( I was traveling about 50mph). At the bottom of this downhill grade was a stop sign. So, I began breaking at a reasonable distance out. Then, about 20 yards out I hit a short (about 2 feet) rough spot in the road. The brakes released for less than a second and reapplied with out my doing anything. The added stopping distance couldn't have been much. But wonder what would have happened if the rough area would have been, say 10 or 20 feet long?? By the way, the anti-lock brake system did not come on.

    Second, I was averaging about 27.3 mpg for about the first 200 miles of driving. Then, before today's short 88 mile trip, I was down to about 26.7 mpg and 300 miles. About 50 of these miles were highway and the rest around town (Stop and go but seveal blocks in between the stops). After todays highway trip at 50-55 mph, I'm again up to 27.4. Unlike the EPA estimates, I'm getting better highway mileage than city. I'm thinking that with a long city type stop and go period, more of the ice gas is used for recharging the battery than is the case during highway driving. In a week or so I am planning a 600 mile trip one way utilizing interstate highways all the way. I'll see what it does at 60-70ish.
  • katzjamrkatzjamr Posts: 146
    in a true emergency your car is equipped with sensors that know you are pushing harder than normal on the brake and will boost the braking power higher than usual, the surge or brake gap will not happen in an emergency, in fact vehicle will stop more quickly.
  • discussion1discussion1 Posts: 103
    I believe your observation is valid.

    I also noticed this sensation of "brake slip" when braking gently after coasting. The slip is so slight and fast, it leaves little time to react. The brakes kick in right after but it is disconcerting the first couple of times.

    When braking more decisively, the slip never happens and the car stops quickly.

    I wonder if when we brake gently enough, the system is still using regenerative braking and not the mechanical brakes. If so, it seems reasonable that when a tire loses traction for a second, the VDIM shifts power to other tires causing the surge sensation because of power transfer.

    It is possible we normally will not feel this function while coasting or with foot on the gas pedal. It becomes detectable when we are on the brakes because the VDIM operates the braking system.

    Just a guess. Someone asked earlier if this is a "problem". I think it is worth a call to Toyota for clarification. If nothing else, the call may cause them to research and look into it. If we all call, they will take it more seriously.
  • wwestwwest Posts: 10,706
    "..brakes released...." "reapplied"

    ABS....

    In the instance you describe your "braking" may have been TOTALLY due to regeneration...

    If so, and the front wheel(s) began to slip (no ground contact momentarily..?), even ever so slightly, in that rough spot (gravel, sand..??) the regeneration would instantly cease operation (release the "brakes") to simulate what would otherwise be a true Anti-lock Braking System, ABS, "function".

    I quite sure, certain sure, Toyota and Lexus wishes they could perform that very same functionality, absent a quick shift into neutral, with engine compression braking. That would improve the overall safety factor of FWD or front biased AWD vehicles substantially.
  • newski3newski3 Posts: 42
    I discounted the cause to be ABS because I did not feel or hear the rapid movement of the brake pedal, which has occurred on all of my other cars when ABS kicks in. Maybe the HH's ABS does not work that way.

    An added note: I do not recall seeing (although I must admit I wasn't looking for) the "slip" warning light as the HH manual describes.

    The rough spot was just that, rough. I did not even see it with my eyes. No sand or other debris was present. There was a slight drizzle so maybe a tire slip occurred??
  • doug28doug28 Posts: 30
    Great information on the mpg.

    I am having very similar results as yours.

    We live in foothill type community and so are usually going up or down a grade of some type.

    Living semi-rural we are getting about 27 mpg but go strictly highway, up & down some serious grades, using cruise and assiting it on the climb till near top, & we are getting 29.4 mpg.

    After highway driving & switching to city we've seen 29.6 mpg. Once we start the semi-rural driving again it drops to 27 mpg or so.

    This is all by the dashboard. We've mannually calculated the mileage and found it to be about 1 mpg lower than the dash but we are comparing dashboard to dashboard with our older family vehcile which averaged about 17.1 mpg in these same driving conditions.

    I too noticed the vechile "surge" while braking. I could be mistaken but found decelerating a little sooner than usual seems to help.
  • cdptrapcdptrap Posts: 485
    Your point about "...front biased AWD vehicle..." makes sense.
    Another question to ask is if the traction system is really active at speed below 25? The manual says all the electronic safety system activates above 25-MPH. So, does this slip thing happen above 25? or under 25? or both? Has anyone noticed the speed when it happens? I will pay attention next time.
  • tmsusatmsusa Posts: 81
    Re the braking sensation you and others here have described, poodlgal, the feeling that you are getting is characteristic of the hybrid braking system on the Highlander Hybrid.

    Not being one of our highly skilled technicians, let me explain simply that the braking system on the vehicle is designed to shift from the Regenerative mode to a pure Hydraulic mode as the Highlander slows to around 8-9 MPH. If you are not accustomed to driving one of our hybrids (same on the Prius, too, BTW), the sensation could initially be a bit disconcerting--But it is perfectly normal.

    When tmsusa first drove the current generation Prius, he too detected a slightly different feeling from traditional braking--also an amazing ability to "coast" seemingly endlessly without the usual slight engine braking feel on traditional vehicles. Great regenerative forward momentum, and made me more attentive to the sea of cars on the 405 here in SoCal!

    Thanks for being a Toyota customer--And as always, if you have any other questions or concerns about your Highlander Hybrid, your Toyota dealer should be able to help. Or give us a call and talk to one of our Customer Experience Center reps at 800-331-4331.
    .
  • cdptrapcdptrap Posts: 485
    TMSUSA, thanks for the informative post. Do you read our board here frequently? It will be great if you can, it is nice to have a Toyota Motor expert in this forum.
  • tmsusatmsusa Posts: 81
    Trying to keep up with it. We're finally recognizing that consumer-generated media--which would include this board--is rich with content that is important to us, particularly as it relates to our customers, products and brand image.

    But it's a bit of a one-man operation now, so certainly can't be everywhere all the time. Now, better get back on-topic before our host boots tmsusa! Thanks for your comments cdptrap.
  • landdriverlanddriver Posts: 607
    I own a non-hybrid HL and noticed it during the one time I test drove a HH -- probably because I'm accustomed to how a HL handles and thus was sensitive to any differences.
  • larry70larry70 Posts: 3
    My 2006 HiHi does not brake properly over ripples or small bumps in the road. It sort of hesitates its braking power.
    Has anyone had this issue checked by the dealer?
    Larry
  • cdptrapcdptrap Posts: 485
    I would ask the dealer just to be safe. But....... ;-)

    Are you refering to situations where you step on the brakes, the car begins to stop and suddenly there is a brief hesitation (1 sec), the cars feels like it is not braking and then quickly it brakes again and stops normally?

    This does not happen all the time, does it? Just occassionally, true?
  • larsblarsb Posts: 8,204
    Is this your first vehicle with ABS?

    I have had several cars and trucks with ABS, and they all have done that when braking hard on ripples or washboard roads.

    It is because the computer gets slightly confused when the tire loses contact with the ground, and the tire loses contact with the road then regains contact with the road over and over and over multiple times in very rapid succession during braking over that type of surface because of the bouncing that the surface causes.

    My recommendation is to plan ahead and slow down more before those surfaces and the ABS will not bother you as much.

    That always seemed to help in my cars.
  • wwestwwest Posts: 10,706
    Yes, since you are relying on "engine compression (regenerative) braking", at least partially, if the anti-lock system should activate, which it is very prone to do in the circumstance you describe, the regenerative braking aspect must be INSTANTLY disabled rather than have it inadvertently interfere with the functionality of the anti-lock system.

    Ford was awarded a US patent that addresses this very thing with regard to regenerative braking on the front wheels of a hybrid vehicle. The patent specifies reducing the regenerative braking level substantially while the OAT is at, below, or near freezing, and disabling it altogether in any or all conditions the INSTANT ABS activates.

    If you browse around on the various FWD and front torque biased AWD vehicle forums on the internet you will find that the industry is striving mightly to solve this very same problem with ALL FWD (and..) vehicles, eliminating the braking effects of the engine on these vehicles so as to reduce the rate of loss of directional control accidents due to loss of stearing capability and from unsafe interference with the functionality of ABS should the roadbed be slippery.
  • I would like to report a problem with the 2006 Highlander Hybrid braking system that also affects the Prius and the Lexus RX.

    When travelling at speeds under 25 mph, the ABS braking systems do not engage in an emergency stop situation. This has been reported on several forums, including http://www.hybridcars.com/forums/brake-failure-2007-t1013.html, and happened to both me (in a 2006 Highlander Hybrid) as well as my neighbor in her Lexus RX.

    In my case, I was travelling around 20 mph on the freeway. The person in front of me unexpectedly came to a complete stop; although I had plenty of space and quickly engaged my brakes, they never "grabbed"--I just slowed and coasted into the car ahead of me. Despite never having been in an accident in my 20+ years of driving, I am now liable for this rear-ender. I hate to think what would happen if a small child ran in front of me on a residential street where speeds are typically under 25 mph.
  • wwestwwest Posts: 10,706
    I think I have read somewhere that the Toyota HSD systems do not (can NOT..!!)use engine vacuum for brake power boost/assist, but use the ABS pumpmotor and brake fluid pressure accumulator system instead. If that is the case it may very well be that an EXTRAORDINARY level of pressure on the brake pedal is required to actually LOCK the front brakes and thereby force the ABS into activation.
  • That is interesting about the way the brakes may work on the hybrids. I was also in a situation prior to this accident where I was travelling around 35 mph and had to slam on the brakes for an emergency stop, and was actually amazed that I did stop in such a short distance. There is most definitely a difference between the way the hybrid brakes act in an emergency situation under 25 mph versus over 25 mph!
  • cdptrapcdptrap Posts: 485
    Hmmm... I do not doubt there are "bad apples" that have brake problems but are you suggesting this is pervasive? I like the info but why the emotive highlights?

    What is the definition and precise specification of "extraordinary"? 200-lb of pressure?

    My wife is a smallish 5-4 and a meager 128-lbs and she has been able to successfully stop this car at low speed (<=25-MPH) without complaints countless times. The only complaint we have is that sensation of "slippage" when the regenerative braking changes to mechanical braking.
  • cdptrapcdptrap Posts: 485
    Sorry to hear of your accident.

    At times, when we travel at low speed and with plenty of room in front, we automatically "meter" how we press on the brakes in order to achieve a smooth stop. Were you doing this and the brakes just did not bite as you would expect? Or did you slam on the brakes and they just did not work?

    We have had to make emergency stops many times at speed lower than 25-mph and the car have always stopped. This is true even when rolling downhill on our driveway at <10 MPH.

    I am not disputing your report, just trying to understand if this is an isolated incident or a potentially bigger problem.

    Thanks!
  • I slammed on my hybrid's brakes, and they did not catch. The exact same thing happened to my neighbor in her Lexus hybrid. I think it may happen when you have been travelling for a while at a slow, steady speed, then make an emergency stop. It's almost as if the brakes have decided that they are in the mode of regenerating and can't make the switch so suddenly to come to a complete, rapid stop. The feeling is one of coasting, as if on ice, at a slow speed. Others have posted of the same feeling on hybrid car and Prius forums--it seems to cross all types of hybrid cars.
  • This forum is the closest that I have found for what we are experiencing on our 2007 HHL. It is an intermittent issue that the Toyota dealership has been unable to provide satisfaction on. The issue first became noticeable to us last winter after about 15000 miles on the car. We now have over 30000 miles on the vehicle. This is our third vehicle with ABS, so we are familiar with how that system feels when it operates.

    First the issue: We intermittently experience the "braking gap" both above and below the 25 mph mark. It is more apt to happen when the car is cold. We live on top of a hill in the rural / suburban northwest corner of CT. Sometimes when we apply the brakes at 30-40 mph for the first stop sign, half way down the hill, the KW needle goes negative indicating regenerative braking, then the regen braking gives up and the needle goes to zero. To stop the car at this juncture, additional brake force is required to engage the hydraulic brakes. Initially we thought it was a cold car / cold weather issue. We have experienced the the "brake gap" in both hot weather and with the vehicle fully warmed up.

    After the last service visit, specifically for this issue, we were told by the hybrid tech that if the high voltage batteries were fully charged that the the regen braking would not engage. We now monitor the battery charge icon. The tech also mentioned that this battery charge icon is not very accurate. The highest level of charge we have seen indicated is a level above the + - signs at the top of the icon. The brake gap usually occurs when the batteries are at least 70% full to full.

    He of course explained how the regen braking would disengage at low speeds. I assured him we were not complaining about that operation. We see and feel that, but it is nowhere near as disconcerting as the free fall feeling when it happens at 35 mph. In full accordance with Murphy's Law, it never happens when driving with the tech in the car.

    Has anyone had any action from Toyota other than attempt to explain away this issue? Is this still considered "normal" behavior?
  • mimersmimers Posts: 7
    I was told by Toyota Customer Relations to contact Toyota's legal department. I have also filed a safety complaint with Consumer Reports, which they were quite interested in, and they recommended the following:

    You may also want to share your experiences with the following
    organizations, which may be able to provide you with information and/or
    offer assistance:

    1. Center for Auto Safety, 1825 Connecticut Ave NW, Suite 330, Washington,
    DC 20009-5708. The CAS compiles information on defective automobiles,
    ranging from transmissions problems to paint problems. If you wish, you
    may send them a letter sharing your experiences with them. Should they
    have any information on your particular automobile, they will forward it to
    you, along with helpful information and advice within 10 days from date of
    receipt of their letter. They ask, but do not require, a $.60 SASE to help
    keep their costs down. Or, you can visit their website at
    http://www.autosafety.org.

    2. Council of Better Business Bureaus, Inc. at 4200 Wilson Boulevard,
    Arlington, VA 22203; 1-703-276-0100. The Council of Better Business
    Bureaus, the umbrella organization for the BBBs, also provides programs and
    publications for consumers, and helps to settle disputes with automobile
    manufacturers through the BBB Auto Line program.

    3. Your State Attorney General's Office, which helps to resolve individual
    consumer complaints, conducts informational and educational programs, and
    enforces consumer protection and fraud laws. You can find their telephone
    number in the blue section of your telephone book.
  • wwestwwest Posts: 10,706
    Were I having the brake problems yawl are describing the first action I would take is HARDWIRE the ABS pumpmotor/relay circuit to the 12 volt battery posts with good heavy duty electrical cables and NO fuse, maybe a 100 amp circuit breaker.

    Maybe even replace the control relay with one that has heavier duty contacts, or 2 pole wired in parallel.
  • cdptrapcdptrap Posts: 485
    THANKS for the detail post and attempt to reproduce. I will try what you post to see if it is repeatable on our '06 HH.

    Yes, as with mimers' explanation, we have experienced this as well. It does not happen often but once in a while, it does happen. Recently, over the past two weeks, it is happening more often as overnight temperature is now down to 50 or below. This was reported quite sometimes back in 2006 when we all first bought and drove the first version of the HH.

    It does seem to happen most often for the first 3 miles. After that, it never happens again. We are also on a hill and shift to "B" for part of the drive and ride the brakes down the rest. It has never happened on this downhill stretch. When it does happen, it is always at one of the stop signs or traffic lights within that 3 mile range.

    We went through this whole summer with hardly any problems. I believe WWest mentioned once before in an informative post that it may have to do with the temperature difference. Something that Ford filed patent for? [WWest: is that true?]

    Anyway, if any of you pursue this far enough and need extra support or more evidence, let us know with a link or a process and I will be happy to add our experience.
  • wwestwwest Posts: 10,706
    There appear to be instances wherein you do not "feel" ABS activation although that is actually what has happened. Ford, on the FEH/MMH will INSTANTLY disable regen if any wheel slips. This is due to ABS activation, but the initial action of ABS is simply to disable regen. You will only "feel" actual ABS "vibration" if the slipping condition persists.

    Since it is clearly NOT a good idea to be using regen braking on a slippery surface ABS may be programmed to be even more sensitive to wheelspin/slip as the OAT declines due to the approaching winter.

    As a safety measure Ford significantly reduces the level of regen available on the FEH/MMH if the OAT is near or below freezing.
  • I love my Highlander Hybrid - but I would hesisate to call the braking problem "perfectly normal." I rear ended a car as I was slowing to a stop when the brakes suddenly reduced their stopping friction ("let go") and before I could react on the rain-soaked road I hit the car's bumper at about 10 mph. I thought I had slipped off of the brake. Wrong. What I discovered is that the braking system is sensitive to bumps while stopping. If you hit a slight bump apparently the hybrid transferance of energy ceases and you're on your regular power brakes. The service supervisor at Toyota is the one who tipped me off to the "bump" problem. Later, going over the same stretch of road, I gently braked and the bump caused exactly the same "release" of friction. It's like hitting a patch of ice! Toyota needs to warn current owners and fix the problem.
  • mimersmimers Posts: 7
    I agree that Toyota needs to warn current owners and fix the problem. I have registered a complaint on the government's NHTSA website, and also on Toyota's website and consumeraffairs.org and with Consumer Reports, who was quite interested, since the same thing happens with the Prius. The more people who register their problem, the more likely something might be fixed.
  • wwestwwest Posts: 10,706
    "..sensitive to "bumps" when stopping...

    All Anti-lock Braking systems have this "sensitivity", undesirable as it may be.

    The "bump" pushes the wheel upward and the shock does not allow it to rebound right away. As a result the wheel loses traction with the roadbed momentarily and the "braked" (Regen ONLY..??) wheel's resulting rotational rate reduction causes an ABS activation.

    The only fix would be to disable ABS...

    Or modify ABS such that it doesn't activate unless VSC indicates the need. ABS has no functional purpose, NONE, unless directional control is somehow threatened during braking. If the vehicle isn't or doesn't yaw during braking, or the driver doesn't need to make corrective directional maneuvers, ABS activation not only serves NO purpose, but can be detrimental, as can be seen here.

    Obviously this effect might be much more detrimental on a modern day FWD hybrid. Up until hitting the bump the braking may be PURELY from Regen, and therefore ONLY on the front wheels. Regen MUST be DISABLED the very instant ABS activates otherwise ABS functionality would be reduced, or maybe even non-existent.

    In point of fact since frictional braking may not have been in use AT ALL at the time of the "bump" the instant disabling of same results in NO BRAKING AT ALL until brake fluid pressure can "arrive".

    There is an indication, Ford has a US patent concerning this, that the Escape/Mariner/Tribute substantially reduces Regen capability when the OAT is below ~34F to reduce the potential for this happenstance.
  • I am fascinated and impressed with the explanation about the ABS system being responsible for the "release" of stopping friction when hitting a bump. However I don't understand how I have missed this peculiarity for the last 20 years I've been driving with ABS and bumps. As I understand it ABS doesn't function unless there is a skid. There was no skid - just a small bump, then the momentary release allowing the vehicle to reduce stopping force. Perhaps you're saying that ABS systems are now sensitive to small bumps, unlike previous generations of ABS and this forces the transition from regen to friction. All I know is that I have had this same "gap" in braking many times as I approach a stop and hit a small bump. Thanks for those responding to this concern.
  • wwestwwest Posts: 10,706
    "...As I understand it ABS doesn't function unless there is a skid..."

    Not these days, technology has moved FORWARD.

    The microprocessors used to control anti-locking are now fast enough that they can PREDICT when a wheel is approaching lockup, "skidding", based on the rate at which the wheel rotation is decaying.

    Have a wheel hit a bump, bound away with no quick rebound due to shock action, and the braking will suddenly become the MAJOR force affecting the wheel rotation rate.

    Anti-lock systems are designed to control hydraulic braking via controlling the brake fluid pressure to each individual wheel using the electric solenoid valves. So the only solution for preventing wheel lockup, skidding, due to regen is to disable regen the INSTANT ABS detects impending wheel lockup.

    The Ford Escape hybrid was using a F/R brake system split so hydraulic braking could be used at the rear simultaneous with (ONLY) regen braking at the front but it appears that with their adoption of a form of VSC this technique was abandoned.
  • Very informative. One has to weigh the trade-off of dangers in allowing for the split-second "skip" in braking during the regen/friction transition or disarming the ABS braking system. Poor choices. Someone needs to invent a system that seamlessly and safely makes that transition. In the meantime, it seems that Toyota should provide a warning to hybrid customers about the braking eccentricities.
  • wwestwwest Posts: 10,706
    I wasn't suggesting "disarming" ABS, just allowing it to activate ONLY when it can be truly functional. If, during braking, light, moderate, heavy, it doesn't matter, the vehicle continues to follow the desired line of travel then the activation of ABS will not just be useless, but in actuality a DANGER.

    An ABS "refinement" that is long overdue now that VSC systems are becoming more commonplace.
  • yotacroyotacro Posts: 5
    I agree with Paracletos that the braking problem has little or nothing to do with bumps inthe road. Have been driving a HH since 06, have had the same problem since day one. When applying brakes, usually but not always, in the early AM on any slight downhill, with no bumps in the road thereis a definite momentary slide to the car before regular braking occurs. I have had ABS brakes on many other vehicles and the action is nothing similar. I believe the prob. is in a switch to regen also. Two days ago three deer darted diagonally across the road in front of me and applied brakes hard and fast and sure enough my vehicle slid a little before braking occured. Barely missed the last deer. Toyota does not respond to repeated reports of this. Locally the only response is they will look into it, even after showing them all the reports of this from Edmunds.com. This is not what I call "Normal" operation of brakes. Thanks for everyones input. Keep reporting this to Govt. safty sites.
  • wwestwwest Posts: 10,706
    "...my vehicle slid a little before braking occurred..."

    I suspect you meant to say: "..slid a little before the anti-lock kicked in..."

    Provided there was no threat to directional control during that "sliding" period your braking was likely more effective than after ABS activated and began to alternately release and reapply brake fluid pressure.

    With a hybrid the initial action of ABS might ONLY be to disable regen. That action ALONE might suffice to remove the impending wheel lockup at the level of hydraulic braking you are currently applying.

    So while you would never "feel" the ABS activation via the pulsing brake pedal in actuality it will have completed it task.
  • I'm more convinced than ever that the problem of "slide" as you call it (and I'm thinking that you are not talking about a wheel "skid") is the same as the "slippage" feel I've referred to in my previous blog post. And whether it is limited to a "bump" or not I do not know - only that it does exist and it's not in our imagination. I'm disappointed with Toyota for the first time since purchasing the vehicle. I was naive enough to think that they would want to know about this problem for the safety of others who are adjusting to this unique hybrid braking system. A rep called me to inquire about the bumper tap as a result of this &#147;slippage&#148; in friction. He acted very interested in obtaining my insurance claim info, etc, until I told him I wasn&#146;t the least bit interested in suing, but rather wanted Toyota to be aware of the problem to avoid a more serious accident, perhaps involving a pedestrian at a cross walk. He simply denied that any problem exists. When I tried to get him to go to this and several other blogs, he &#147;proved&#148; that these bloggers have no credence by instead Googling &#147;Honda braking problems&#148; to show me that any car can have people complaining. I felt that my concerns were totally invalidated. He asked if I had reported my &#147;supposed problem&#148; to the service department at the Toyota dealer. When I said that it was the service manager that first identified the issue by asking me, &#147;was it when you hit a bump?&#148;, and it was the service mgr who indicated that this was a common eccentricity of the HH. The Toyota rep simply told me that the service manager probably didn&#146;t mean that. I have enjoyed this vehicle, in spite of the braking problem, but am very disappointed in Toyota&#146;s response of &#147;litigious denial.&#148;
  • wwestwwest Posts: 10,706
    "..missed this (ABS) peculiarity for the past 20 years..."

    "..before I could react on the rain-soaked road..."

    "..rain-soaked road.."

    Primed for ABS activation.......

    With very little experience with ABS we begin to expect that brake pedal throb/vibration the instant ABS activates. But now with a hybrid you have two sources of braking capability. With a hybrid when your Anti-lock system initially detects that a wheel or wheels are approaching lockup/skid/slide (the wheel's rotation rate is decaying TOO rapidly) the first action of the ABS will be to INSTANTLY disable regen braking. It is entirely possible that the disabling of regen will resolve the problem in its entirety and now "you" are left setting there wondering why the braking suddenly got weaker just momentarily.

    Following a bit TOO close for conditions...??!!
  • wvgasguywvgasguy Posts: 1,405
    . It is entirely possible that the disabling of regen will resolve the problem in its entirety and now "you" are left setting there wondering why the braking suddenly got weaker just momentarily.

    All this may be true about the ABS and emergency stops, but the "feeling" is there even in a non emergency stop situation or without hitting bumps. I live on a steep hill and generally go down with the intent of riding my brakes to help charge the battery and warm up the engine. It's a long hill, about a quarter of a mile. I drive about 20 - 25 mph during this time. Near the bottom of the hill there is a sharp curve at the same point that the slope lessens. Almost 100% of the time as I approach this area I get the sensation that my brakes briefly quit. However I believe that the sensation I get is the switchover and that it should not be a cause of concern, or at least if I realize this sensation will occur. It is a little unnerving at first, but the HH appears to slow at the same rate.

    I liken this feeling to the same one people complained about with the TCH on initial takeoff. Many complained that when they floored the gas there seemed to be a hesitation. In reality, the torque of the electric motor immediately started the car in motion and then the ICE kicked in. They felt the ICE kick in and it gives the sensation that the motor by itself was not doing the job. I believe that to be a feeling, not a fact. The TCH is a quick car, much faster on acceleration than most "sporting" sedans of the 80's. Much quicker than the 4cy ICE only Camry.

    It is quite possible that a person could be in the wrong place at the wrong time and the worst happened; all you could remember is that the brakes felt like they gave away briefly.

    From what I've learned so far from driving a hybrid, thereare a lot of things with a hybrid they should tell new customers. They should describe some of the quirks and sounds that you will hear, and assure you it's the nature of the beast. It's a different machine than you've had in the past.

    Sorry to say this, but my opinion is that if someone slid into the back of another car with the HH, then they were driving too fast or following too close. I don't believe the momentary "feeling" in and of itself whould be a contributing factor in a wreck.
  • yotacroyotacro Posts: 5
    I,m not sure what the recommended following distance is from three deer crossing the road in front of you diagonally is, but-----what I do know is that with the 06 HH you can repeat the brake slide(not wheel skid)on a slight downgrade repeatedly. I have been able to repeat the slide three times on one short run even at slow speeds. This I have done at speeds which the ABS should not have egaged and on completely smooth dry roads. I have also had ABS brakes engage properly at sandy road intersections and believe I know what that should feel like. I don't find,"Following TOO close for conditions...??!!," helpful.
  • wwestwwest Posts: 10,706
    Sorry, but can you tell us what you mean by "brake slide"..as opposed to "wheel skid"..??

    And personally I do not know of ANY road speed and/or road condition wherein ABS should NOT engage.
  • cdptrapcdptrap Posts: 485
    Looks like this "slip" is continuing to bother and puzzle HH owners. Toyota needs to have an answer.

    This slippage is periodic, it seems. I thought it was a bump once, not any more. Then I thought it was temperature but not that either. Now I think it is likely just brakes warming up or something warming up.

    Not bumps because it would happen even on perfectly flat asphalt. On a dirt road with pot holes, it does not slip. Not temperature because we have driven in snow and ice and the car did not slip and stopped dead straight on clear ice that we thought were water.

    When it does happen, it is often within the first two to three miles after starting from a cold engine. I am beginning to think it has something to do with something NOT warming up. After the first three miles, it never happens again.

    Even when it does happen, the car continues to slow and stop as intended. We have never had problems with "run away", at least not yet.
  • wvgasguywvgasguy Posts: 1,405
    I don't find,"Following TOO close for conditions...??!!," helpful.

    The "slide" I've experienced is very brief and I don't believe it is really anything other than a sensation one feels rather than a performance issue.

    As far as being "helpful", 99.9% of the time you run into the back of someone you were driving too close or not paying attention. Hitting deer is a completely different situation.
  • wwestwwest Posts: 10,706
    "following too close"

    I was referring to the "bumper tap" post.
  • yotacroyotacro Posts: 5
    In trying to determine the exact area of concern when experiencing brake slide, I guess the only way to explain this actual slide as opposed to perceived slide, is to say that when a vehicle slows or stops as we would expect 97% of the time when going down the road or approaching a stop--but then when you expect your brakes to do their job and they all of a sudden don't slow or react as you have come to expect--there is a problem. When this condition, on a given morning, can be replicated, time and again, you know it to be true. If you were walking down the street and your heart stopped for a half a second, you would probably know that it had happened. You may not know why or how but you for sure would know that it was not normal--as you know normal. Each and every time you stop your car ABS does not activate. A certain condition should exist before activation--as I understand it--maybe I'm mistaken. If those certain conditions don't exist-my understanding is-that the ABS would not activate, i.e. sandy road condition, wet road, one or more wheel skid, etc. thus setting off ABS.
    Please understand that I think my 06 HH is the best vehicle I have owned. It has brought me on many long trips to Minnesota and back twice, to Branson, Mo. to No. Carolina three times and back safely and without one breakdown. I would buy one again and probably will. As a matter of fact-I am headed this AM to pick up a new Prius because I believe in their technology. I think probably the 2010 is even better but our 09 will have to do for now. Hopefully we will keep our local yota dealer in business and a few salesmen working. My objective is only to keep Toyota painfully aware that this is not something just in our head or a perceived feeling. Thank you all for your patience.
Sign In or Register to comment.