unintended acceleration & brake failure
 

Just brought my 2007 TCH to dealer after using a small tree to park the car. This is 2nd occurrence of unintended acceleration and brake failure.
The first, in my garage, with 6 inches to go, had foot on brake lightly
and was moving at 3 KPH. Sudden acceleration caused my foot to slam
down on brake, but still required almost 18 inches to stop the car. Had 1 inch to spare before using the front bumper to get some beers out of the fridge.

Then, yesterday, was parking again at 3 KPH with 12 inches to go when 'TCH-HAL' took over. Slammed on the brake, but too little, too late. The brake pedal felt like the car was totally turned off and I was braking without any help from 'TCH-HAL'.

Unfortunately, can't recall for sure if I was on battery and the ICE kicked-in, or if I was still running with the ICE on.

There are no floor mats to blame and I know the difference between gas and brake.

This time it was a tree, what if it was a human being !!!!!!!!!

Anyone out there experience this before. No, it's not your imagination, no you didn't get your pedals all mixed up, no, no, no.:angry:

Re: unintended acceleration & brake failure
 

lubo,

Several questions and one statement.

1) Have you owned the car since it was new?
2) How many miles are on the car?
3) Do you left foot brake?

After 23,000+ miles I admit that this has never happened on my Camry and the last case of "unintended acceleration" I experienced was 20 years ago on a horse. Note: I no longer own a horse...

Re: unintended acceleration & brake failure
 

You don't say how long you've had the TCH. I say that because 'newbies' to the TCH are often surprised at how easily the TCH keeps on rolling even after you have your foot off the gas pedal. Wth no engine braking to help slow you down you have to be quicker to hit the brakes even at slow speeds. I notice this effect every time I switch between my TCH and my wife's Avalon.

Unless you have a true malfunction, it doesn't matter whether the ICE was on or not since all power goes through the PSD to the wheels.

Re: unintended acceleration & brake failure
 

:rolleyes:Ya, this happens all the time when you let your brain disengage!Called a brain F#$%.ROTFFLMAO

Re: unintended acceleration & brake failure
 

Did I read some idiot's comment on this matter?

Well, I'll raise my (wife's) hand in our '06 Prius. She was driving support for me during a cross Wisconsin bike tour. From her description of the event, the Prius suddenly accelerated.

She **** near stood on the brake before she finally got the car stopped, left front brake afire, the right one smoking. Fortunately she was able to find a farmer who was waiting for his mail to run into his house and get a fire extinguisher.

The dealer in Wausau, Wi (where the car was towed and repaired) showed me a pict of the carpet over the accelerator pedal, tho my test of this possibility was not able to confirm.

Shortly after I posted the event on this website, an owner of a new Prius emailed me telling me of that problem, I think, exiting a freeway in Washington state.

I have a friend who is a freelance photographer and does some shooting for Toyota. So, when she asked what the cause could be, she was told that the problem was with doubling of floor mats (do you have the nifty Toyota all weather mats atop your faux felt mats).

So, not wanting to argue with her I just removed the original mats and made sure I've anchored the rubber mats.

Re: unintended acceleration & brake failure
 

Is this comment offered as a solution?

Re: unintended acceleration & brake failure
 

There is a recall on the floor mats, because they could trap the accelerator pedal. A lot of people put the winter (rubber) mats on top of the summer (carpet) mats. The two mats, together, were too thick to engage the hook on the floor. The result was that the rubber mat would slide forward and catch the lower edge of the pedal. When that happens, you can still see most of the accelerator pedal, so it is difficult to even realize what has happened.

The replacement rubber mats just have a warning to remove the carpet mats, use only one floor mat at a time, and to make sure the hook is engaged.

The photos in the recall notice show clearly that, when the rubber mat catches the lower edge of the pedal, it is not obvious. When the rubber mat is operating the gas pedal, you can still see (almost) the entire gas pedal.
http://www.nhtsa.dot.gov/portal/site...earSelect=2007

Re: unintended acceleration & brake failure
 

Thanks, Steve.

That doesn't seem to solve the problem of the originator of this thread and the Washington acceleration.

I've removed that original mats, and so - over 40,000 miles later the car runs beautifully.

Recall? When did Toyota put out a recall?

Re: unintended acceleration & brake failure
 

The carpet slips forward and gets trapped under the brake pedal but OVER the gas pedal and then when you step on the brake pedal and it moves forward so does the gas pedal.

Re: unintended acceleration & brake failure
 

Martin,

Toyota recalled the all weather mats over a year ago. The new ones have a cutout for the gas pedal as noted above. I gave up waiting on them and bought Weathertechs instead.

Re: unintended acceleration & brake failure
 

Maybe. However, my wife is just over 5'1'' stood on the brake peddle at the Wausau dealer and I was able to get my fist under, i.e. between the bottom of the peddle and the mat.

Another point: As their photo showed, the carpet (by the way, I'm sure the photo was staged) was over the bottom of the accelerator, so I don't think enough leverage could be applied by the carpet(s) to depress the accelerator.

When I got to the car, the engine was off. My wife was alongside the Prius. After hearing of the event, I got into the car and started it - No racing of the engine. If she kicked the carpet away without realizing it, than how did it manage to crawl up that accelerator?

Finally, this thread is not about my Prius, it's about a new TCH. I realize that my event distracted from the original intent of the thread.

Re: unintended acceleration & brake failure
 

Thanks for the info. My '06 Prius' seem to have a cutout, i.e., the mat slips under the brake peddle and than descends down and around the accelerator. Unless the cutout is deeper. Or is it that the Camry's mat was designed differently than the Prius.

Re: unintended acceleration & brake failure
 

The original Camry mats did not have a deep cutout, the newer ones do.

For the original poster, I was asking the questions for a reason. If left foot braking, some people MIGHT lightly tap the accelerator pedal to ease a car into a garage or up a slight incline. There are a LOT of late model cars (including the TCH) that have an electronically controlled throttle body. When it gets dirty (not if, but when) it can "stick" in the closed position.

When that happens, the servo motor will try to slightly open the throttle and not be able too which causes an increase in torque applied by the servo to open the throttle. At some point the throttle WILL open and when it does an over rev condition will occur before the servo cuts the rpms back to what is desired.

My old 2000 S80 Volvo was known for this problem (I had to clean the Throttle body every 5,000 to 10,000 miles) and I suspect that is the issue here. Preventive maintenance on all of my vehicles includes cleaning the throttle body ever 40,000 miles (every other air filter change).

Note that this will NOT result in the engine being throttled up for an extended time period of 3 or 4 seconds or more but just a "blip" of maybe a second at the most. If you are not expecting it, you will be caught off guard and have a "boo-boo". Your throttle body might need to be cleaned more often if used in dirty/dusty conditions, used with a “oil” type filter or if the airbox is not sealed correctly.

If you right foot brake, the only way this could happen is if you remove your foot from the brake and pressed the accelerator or you “heel and toe” like you would with a manual shift car. I would hope that you would remember doing that….

Re: unintended acceleration & brake failure
 

Lubo said, he did not have the factory mats. I passed them up myself due to the price, when I bought my new '07 TCH. My wife bought some just fit gray carpet at Walmart that cost $5 per side. I replace them annually to keep them looking new.

I did own a new 2006 Ford Five Hundred. I had a similar problem getting the car to stop at some red lights. I discovered my brake pedal on the Ford was near to the floor. I found I was stepping on the brake and the accelerator at the same time. I had some close calls with red lights and stop signs due to this problem. I could hear the engine trying to pull while I was frantically trying to stop the car.

I called and talked to the Ford shop foreman. When I mentioned the low brake pedal on the new Ford, he asked if I used the emergency brake when the car is parked. I said, I used to on my Chevy but decided not to on the new Ford.

He said, even though the Ford has 4 wheel disk brakes it still uses the emergency brake to adjust up the rears. I started using the emergency brake and sure enough within 3 or 4 days the brakes were full up and so much easier to stop. This also eliminated my problem of pressing the brake and accelerator at the same time.

Our TCH has a similar rear drum brake within the main disk brakes. I have no idea if using the emergency brake on the TCH when parked would help your particular problem. I do know if your main brake is down very low when pressed, that makes it possible to press the accelerator and brake at the same time. I never have looked at the brake and accelerator separation.

If your main brake pedal is low, have the dealer check it out. I have never had any problems like this at all with my 15,550 mile TCH.

Re: unintended acceleration & brake failure
 

The "cutout" doesn't "cut" it...!!!

The problem is that an "untethered" floor mat slips/slides forward (might take weeks or even a year), covers the gas pedal, and then when you apply the brakes you get braking and engine acceleration.

Re: unintended acceleration & brake failure
 

ok, let's say, the mat caused the acceleration,
why did the brakes fail? Trying shutting down TCH (completely)
and press on the brake. No power, no brake.
Is my floor mat responsible for that too?

Lubo

Re: unintended acceleration & brake failure
 

1-TCH does not have disc-drum setup, it's all DISC, front and rear.
2-TCH driver side floor mat has a hook and eyelet setup. If the hook is
set it, you could dance on it and the mat will stay attached. The reason,
the hook is on a swivel base, wherever the carpet goes, so does the hook.
Result, my floor mat has never, ever seperated, or moved from its intended
location, i.e. under my feet rather that accelerating on the gas, and doing
the reverse on the brake.
Don't you think at all odd, that not only must the mat slide over the gas
pedal, but also, slide under the brake. Come on folks, a little common sense
here, a mat is a mat is a mat. Not Houdini, or some Barnum & Bailey contortionist!

Lubo

Re: unintended acceleration & brake failure
 

:omg:What R U smoking? Your #1 is waaay off! The TCH uses a disk-drum setup on the rears for the park brakes, read up!!!:rolleyes::rolleyes::rolleyes:

Re: unintended acceleration & brake failure
 

With the TCH shut down, the brakes still work, it just requires more pressure (a lot more). The feel is similar to a conventional car when the power brakes fail.

Re: unintended acceleration & brake failure
 

thanks Nash,
Just checked with Toyota dealer. There are 2 potentiometers, one in the accelerator, and the other on the throttle body. If they don't match, it's auto-shut down time, and an system error code is transmitted.
But thanks, it was a good idea, but the technology has changed. For the better, at this point, I don't know.

Lubo

Re: unintended acceleration & brake failure
 

I checked up on that a few days ago investigating, if the emergency brake auto adjust up the rears. It does not, they are manually adjusted smaller drum brakes. The drum brakes are about 6" in diameter and are connected by cable to the emergency brake. They are called dual rear brakes.

With the engine off the car can be stopped but it takes lots of peddle pressure to do so. The reason being when the engine is off the power booster is also off.

click picture for large view

Re: unintended acceleration & brake failure
 

come on, guys....this has always been a friendly forum, we often disagree, but let's keep it friendly

Re: unintended acceleration & brake failure
 

GMAN has some kinda problem which I hope he solves soon.

Keep in mind I drive a Prius (and I am not a lawyer, but a retired biology teacher). But here is a possible course of action:

After my Wisconsin run-a-way, I considered taking Toyota to the mat. That is, I was going to go into arbitration on the matter because at the time my insurance was not going to cover the cost of replacing the burned out front brakes.

In Calif., if one looses in arbitration one can request a trial.

As it happened my insurance paid for the brakes, the car rental, and my motels. So, I dropped the idea.

That's it. I'm clueless as to what could have possibly caused your problem or mine, but good luck.

Re: unintended acceleration & brake failure
 

Upon appeal, the thread is open. Keep it professional and everything will be OK.

Now if you think someone is being abusive (besides the moderator in whom we all live in fear,) use the triangle-bang "https://www.greenhybrid.com/discuss/...ons/report.gif" to report the problem. There is no need to go down that hole ... that is our job.

Thanks,
Bob Wilson

Re: unintended acceleration & brake failure
 

Thanks everyone for the possible insight into my unique problem. My 2007 TCH was one of the first of the production line, so maybe it's limited to a small batch. There's also not that much time or mileage to perhaps pickup a trend. I'm filing with Transport Canada
my safety concerns with this possible defect. If there will be enough cases, they'll talk to Toyota about a recall, and I would join a class-action lawsuit to recover cost of damages.
In the meantime, I'm keeping my hand on the transmission, when parking and slowing down, to try to quickly shift into Neutral should there be a sudden acceleration.
If it happens again, the car goes back to Toyota. I'll buy the newest Prius coming out in the spring. I'm also thinking of picking up an electric motorcycle with a 40 mile range. Just perfect for day trips around town. There are currently 3 manufacturers selling in North America. There's one, TTX01 that has a top speed of 125mph.
Some of the others: EVT-4000, Brammo Enertia, Zero-X dirt bike,
Motorsport GPR-S, UNO, Vectrix, Aptera, with Honda and Yamaha about 12 months away from producing their own lineup.

thanks,
Lubo

p.s. sorry, got carried away with electric bikes there

Re: unintended acceleration & brake failure
 

So, you're Canadian. Good for you. I get up to Toronto about every other year as I have friends in Windsor & Tor.

Nice exchange of ideas.

Re: unintended acceleration & brake failure
 

I have experienced pulling into a garage in electric mode and the ICE kicks on just as you are creeping up to the last 6 inches of your stop, it "sounds" like it is accelerating and you do get a slight surge, which causes you to step hard on the brake, but I would not call this unintended acceleration. Remember, I am a Toyota Service Manager and I have seen zero cases of "unintended acceleration" that were not related to driver error (double floor mats, snow boots hitting both pedals, etc). If there were truly an unintended acceleration, there would be some data (codes, etc) in the computer to show a faulty sensor and lights would light up the dash like a christmas tree. Once again, zero cases reported in our local area (Northeast).

Re: unintended acceleration & brake failure
 

P.S. it does "wake you up" when it happens. You are not expecting it, but if the engine is required to charge battery, cats are cold, etc., then it is normal operation of the vehicle. Does it surprise you when it happens? Of course it does. I still would not trade ours for the world.

Re: unintended acceleration & brake failure
 

OK on your in the EV Mode when you enter the headed into the garage. The only thing that would kick on the engine is if you lightly touched the accelerator. Perhaps the car rolls over a concrete rain strip to keep any rain water out of the garage. The ones I have seen are only a half inch high.

The only other reason the engine may start is if the traction battery is at a minimum charge.

Re: unintended acceleration & brake failure
 

Actually in cold weather, the heater can drop the temp of the ICE below the threshold needed for EV operation, and cause the ICE to start. ;)

Re: unintended acceleration & brake failure
 

All of which happens to me, but does not match the description of my wife's experience as she fought for control in order to avoid running down bicyclist on the road that day.

The ICE usually comes on with a kinda lurch. Because It's happened at stop lights/stop signs, I don't worry about it. Besides, I'm rolling into the garage with my foot on the brake.

I'm not impugning your honesty, but it is certainly possible that the Toyota Rep (he who photographed the mat over the accelerator pedal) could have lied about the codes.

So, keep in mind: My wife is around 5'1", 5'2", small feet, summer so no snow boot and the cutout of the mats around the accelerator peddle, plus the height of peddle above the mats makes in very unlikely that the (a) mats climbed up the accelerator, and (b) that the brake peddle could have made contact with the mat as the brake peddle was depressed.

Nice hearing from a dealer. You guys are on the front line. The service reps at Toyota of LB were super. And than Hooman bought them out. Now I'm considering having oil changed and wheel/tire work done at a local shop.

Re: unintended acceleration & brake failure
 

Methinks it may be time for a "failsafe" circuit/system design like the one that prevents you from shifting out of park absent a firm foot on the brake.

A failsafe circuit that "forces" the throttle (DBW, E-throttle) to close fully if the brake is applied, maybe including the parking brake. That would also put a stop to left foot brakers driving along for miles and miles with their left foot "resting" on the brake pedal, wasting fuel and wearing the brake pads out prematurely.

And I suspect many of us, like me, are finding the new LED brake lights FAR TOO BRIGHT.

Re: unintended acceleration & brake failure
 

Yup, I remember couple years ago when this happened to me for the first time. Wooo! It was very startling, especially since I had the windows down and the engine noise echoed from the garage walls made it sound really loud. But the only unintended acceleration was my heart! Took me a minute to calm down after that. Now when it happens it's more like "crap, an engine start just 2 seconds away from shutdown, what a waste, oh well".

Re: unintended acceleration & brake failure
 

I have a story for you guys with the issue of "lurching"
First time when I had to change my oil for the Camry HV, I used my old drive up ramps to get under the car. 1st time successful, I even drove up the ramps without a "spotter" outside telling me when to stop.

2nd time comes around to change the oil...I drive up the ramps with a spotter, the guy tells me I am getting closer to the end. Well, it was in EV mode/electric while going up the ramp and all of a sudden the gas engine kicks in and the car lurches forward, overshoots the ramp, and falls off it!
The ramp was stuck under the car until I had to use a jack to raise the car to remove it. Lesson learned: don't use ramps to change the oil for this car, its very hard to drive up the ramp because all of a sudden the gas engine might kick in and shoot the car forward. Now I have been using the hydraulic jack ever since....

Re: unintended acceleration & brake failure
 

This can be avoided!

Place the TCH in "B".
If the ICE is not running, firmly hold your foot on the brake pedal and tap the gas pedal. The ICE will start.
Slowly drive up the ramps, and the ICE will stay running.

When the TCH is in "B" the ICE will not shut off once it is running.

Re: unintended acceleration & brake failure
 

IN 10,000 miles, I've never experienced a "lurch" when the ICE kicks in. I find the transition from E-mode to ICE very smooth. Perhaps this will change as the car ages.

Regarding the whole "stuck throttle" issue, several years ago NASCAR mandated a "kill switch" on the steering wheel after a few incidents of drivers being killed after hitting the wall with a stuck throttle (Adam Petty comes to mind, but I know there were a couple others as well).

The problem with the kill switch is that drivers are not conditioned to use it, so it takes a long time. What drivers ARE conditioned to do is hit the brakes, so Roush Racing came up with an alternative solution. The car has a device that will kill the engine if it detects significant brake pressure in combination with significant air flow to the engine (meaning the motor's running wide open but you mashed the brakes). This is a pretty low-tech solution and would make sense to me to be installed on all passenger cars.

(Note: Roush cars still must have the NASCAR mandated kill switch since that's the only "approved" solution in the rules.)

Re: unintended acceleration & brake failure
 

Close to 50 K and I've experienced the, "lurch" but most while the ICE is cold. Still, a prudent driver would enter the garage with foot on the brake.

The lurch is not forward but kinda side-to-side. As if one is shuting down a standard ICE with a key. The car does not charge forward.

For Toyota to start installing kill switches in their cars presents a whole host of problems for them including an admission of the probability of such an event happening.

Re: unintended acceleration & brake failure
 

For clarity, I did not intend to suggest that Toyota or ANY manufacturer install kill switches. I was pointing out that there is an unobtrusive bit of programming that can be done to add an extra margin of safety to ALL vehicles, and that would be the brake pressure/air flow interlock.

Re: unintended acceleration & brake failure
 

"..kill switches.."

No, just something to complement the already existing park/brake lockout, itself introduced to help prevent inadvertent instances of sudden unintended acceleration.

Re: unintended acceleration & brake failure
 

Could you send an email to Tim at the Automobile Protection Association, here in Montreal ? He is doing some research and would like to ask you some questions about your experience with your car.
His email: apamontreal@apa.ca
My email: hotlubo@hotmail.com

thanks very much,
Lubo

p.s. have not had any more problems with my TCH, but am in
touch with Transport Canada about at least 1 other similar
occurence. If you wish, I can keep you up-to-date through
your email rather than this post at GreenHybrid.