Jump to content

Registered users (members) don’t see this ad!

Sign in to follow this  
icecreamxd

Unintentional Acceleration

Recommended Posts

A few weeks ago, my dad was driving a 2007 Toyota Corolla and it suddenly just accelerated on its own. He tried stomping on the brake pedal... nothing... Even put it on neutral and still nothing.. My dad eventually had to crash the car into a curb and it finally stopped. Damages were minimal but I'm sure the feeling was unforgettable. Everyone had heard about this issue but with the 2009 or 2010 model so it was very strange that it would happen to the 2007 version after owning it for 7 years or so. The car seemed normal after that but my dad was scared as hell to drive it.. He took it to the Toyota dealership to inspect it. After a few days, they gave the car back with no status update. Toyota Corporate has been notified but still didn't do anything about it. After a while my dad got sick of waiting around and traded it in for a brand new car with the Nissan dealership. The corolla was worth practically nothing because of high mileage but he feels so much better that he got rid of it.. We have bought nothing but Toyota's over the years and have been unsatisfied with many things that have happened so my dad made up his mind to never buy another Toyota again. I don't blame him. I might still consider a Toyota again in the future but am swaying away from it for various reasons other than this. I myself own a 2004 Corolla and it feels totally different than the 2007 one even though they are the same 9th generation. Something was always off with the 2007 Corolla and it's not a surprise what happened. This is just a warning for those who own the corolla around the time the big recall happened.

Share this post


Link to post
Share on other sites
trap

Your 2004 has a cable operated throttlebody vs the 2007 DBW setup - so unless you had something physcially propping up the throttle, no way to get the throttle stuck like that.

 

As for stomping the brakes - even the most power car will be able to pull to a stop even with the throttle pinned wide open - if your dad pumped the brakes, that is a different story. In that case, that would have been the worse thing he could have done - as it would have bleed off vacuum used to boost the brakes. Even then, the car would have still come to the stop - but would have taken more time.

Did he pump the accelerator pedal as well? If it was a pedal issue, may or may not have "loosen" up something there as well.

 

Dropping the car into neutral would have always worked - as that is still a phyisical connection, even in the cars that were reported to have unintended acceleration - if the throttle was truely stuck, engine would have raced, but the wheels would have no longer been under power - it would have rolled to a stop eventually. Sounds like he may have missed neutral position and still had it in gear - crashing into the curb could have popped the shifter into neutral - as this gen has the straight back and forth PRNDL2 gear selection. My Camry is the same way - some years ago when I spun it on the highway due to hitting an ice ramp (water that drips off a bridge, freezes to the roadway below making for a mini ramp, launching the car high enough to unload the suspension) - the car nosed into a snowbank and the momentum forced the shifter into neutral.

 

Sorry he felt that he had to dump the car, but it was his car, his choice. Toyota corporate couldn't do anything because it was already proven that no outside electrical interference could have tripped up the DBW. Assumignthe dealership didn't find anything during their diagnostic. Assuming they did a ECM program check with TechFlash software? Checked to see if the return on the pedal assembly was within spec? Pedal misapplication / pedal interference were the major factors in unintended acceleration discovered from the blackbox studies done by a number of forensic shops.

 

Appreciate the concern though, haven't heard much of any reports recently, since the media frenzy on SUA. I remember back with the old cabled carburated cars - stuck throttles were pretty much a common occurance. I'd actually be shocked if the throttle didn't get pinned down because of a stuck throttle plate or sometimes broken throttle return spring.

Edited by fishexpo101

Share this post


Link to post
Share on other sites

Never fails....just as we were getting ready to purchase another Corolla (used 2011-2013) I see on the news today there is issue again with the above post of acceleration issues. We love our 2005 LE....best car we've owned and running strong, looking great at 155K. But my wife is horrified of any acceleration issues so now wants us to look at something else. Even she hates the interior of the Civic so that's probably out....Fords have tranny issues.

 

Fish...Dom....anyone...know why they are saying its 2006-2010's Corollas??? Are those years the only ones with complaints? Could this spread to 2011's and later??

 

What the heck is going on again?!!

Edited by cirrus

Share this post


Link to post
Share on other sites

Hard to say for sure - some owner's swear they ran into this issue, some just want to jump on the bandwagon and cash out. As for the models that are effected - potentially any car with DBW systems (ie, most cars on the road now) - can run into a situation. Can't say that it can never happen - as I feel that some owners truly have run into SUA, If this was do to some issue with the ECM or electronics or incredibly bad luck - is anyone's guess right now. FWIW - Toyota was found not at fault in the electronics side.

 

Myself - never ran into SUA on any of my Toyotas (DBW). Toyota was late to the party in having a throttle shutoff - so called "Smart-Stop" campaign they are running now. Basically a ECU reflash that in the event of simultaneous brake and accelerator pedal application - car will kill the throttle for 10-30 seconds. Similar system to what other manufacturer's have right now. IMO - this is a knee-jerk reaction to some very isolated cases of SUA that eventually turned into a media frenzy.

I remember back in the old carburated days - throttle springs can break, cables get stuck all the time - I couldn't remember a week where the throttle didn't get stuck at some point. Remember the old Audi stuck accelerator pedals? Ended up being the pedals being spaced closed together for efficient heel-and-toeing that the major factor, as owners were stomping on both the accelerator and brake pedal at the same time. Driver error was what Audi blamed it on and the courts agreed - but it almost bankrupted the company as public opinion on Audi dropped to nearly zero.

 

Remember that NASA and other forensics experts poured over all aspects of Toyota's DBW system on several models and concluded that there was no failure mode that could cause SUA. They conclusion was similar to what Audi found - driver error. The media frenzy was accompanied this SUA rocket - suddenly died off as soon as it started.

 

Its one of those things that you deal with it when it happens - to avoid it all together and jump to another model is a non-solution, as it could effect any manufacturer out there. Me - I was looking at a 2005-2015 Toyota product - SUA wouldn't even be an issue for me.

Edited by fishexpo101

Share this post


Link to post
Share on other sites

From what I'm hearing/reading they have cases of where the ECM data(?) doesn't show the accelerator being depressed...the brakes on....yet the data shows the motor rpm's had risen just as the drivers said.

 

For sure some are driver error....but I've been around engineering issues far to long to not also know this is probably a real issue for some cars. I also spent years working in the embedded software field and had to many experts tell us nothing was wrong when a year later we in fact found code issues. One time we had the EMC code being corrupted by a very bizarre EMC issue....took us almost 6 months to fix it as it took that long to recreate it. I'd like to see the NASA report....if they did recreate it and it wasn't electrical or never recreated it. In either case (whether electrical or mechanical) its a serious case for concern as I cant afford any type of accidents.

 

Its true it can happen to any car...and I haven't looked to see if others have had this issue but it seems Toy has had more than their share of this issue...or at least owners saying that.

 

WHen did Toy start using the "Smart Stop" technology?

Share this post


Link to post
Share on other sites

I've haven't seen anything like that. I've seen ECM data that shows both the gas and brake being depressed. There was that one case where an Avalon? was brought into the dealership with the throttle pinned, car in neutral - but that was a very unusual case. As both ends of the variable resistor (in the gas pedal, APP circuit) were shorted to supply voltage. Didn't catch what details there were, but it was only reproducible by the forensics team (Safety Research and Strategies, Inc.) by backprobing the wiring and adding wire taps. Basically, they had to intentionally short out the wiring to cause this malfunction.

Doesn't mean that Toyota is completely out of the loop - the same forensics team found that there are certain combinations of failure modes that are not captured by the ECM. It all boiled down to how Toyota ECM handled unusual failure modes of the APP circuit. By design, the circuit could not lend itself to additional redundancies (ie, the pedal assembly had two Hall Effect sensors, two separate voltage sources for redundancy), but they wanted to see redundancy in the voltages as well (instead of two rising voltage waveforms with similar slopes, they wanted to see two waveforms with offset voltages and different slopes). So that more failure modes could be detectable.

 

I found it pretty interesting myself - with a background in electronics, physics, and engineering - computational physicist by education, government contractor working in a R&D firm on lots of "interesting" projects - both hardware and software. From what I've seen so far - the ECT and DBW system are pretty robust, but like you said - it only takes one case of a perfect storm of mechanical issues and software limitations to cause a catastrophic failure mode. The preliminary team found that there are holes in the detectable failure modes (granted, they intentionally caused non-standard failures - 4 vehicle sample) - but still, would liked to have seen the ECM atleast come up with some code saying something is wrong. NASA findings explored if there was any case of transaxle not going into neutral, brake control stripped from the operator, EMF/RFI interference, and circuit forensics (infamous tin whiskers issue) on their fleet of 58 cars that were reported to have shown SUA, only 39 with high or increasing throttle position of which 35 showed no sustained brake pedal application on the EDR boxes, the rest didn't show it or their EDR didn't have any useable data.

 

As far as other manufacturers running into similar things - lookup SUA for Dodge and VW/Audi. Actually more cars affected there than Toyota - but Toyota having a reputation for bulletproof reliability and some tragic accidents (that Lexus ES350 on in 2009) that were sensationalized by the media - everyone was painting Toyota to be the worse of the bunch. Car and Driver posted a chart that showed the instances of SUA in Toyota sykrocketed after 2009 - but as soon as the final report came out - incidences dropped to about average.

 

http://www.caranddriver.com/features/its-all-your-fault-the-dot-renders-its-verdict-on-toyotas-unintended-acceleration-scare-feature

 

As for the PDFs, both the preliminary document and the NASA finds should be in PDF form on the web. I've Googled them up before, but don't have the links handy.

 

As for Toyota "Smart Stop" brake override fix - that I think was this year (2014) - when some owners were notified. There is an ongoing thread on the Rav4world forums - one owner reported seeing a drop in MPG, others haven't seen anything different. But all have indicated a marked different in throttle behavior. Some liked it, some didn't. The trail/off-road owners were really upset that you couldn't hold throttle and apply brakes simultaneously - Smart Stop did allow it to happen only at very low speeds in 4 wheel lock mode only.

Myself - I'm still waiting until the dust clears. My dad's shop was initially involved in some of the forensic work - especially in the cases of trying to pull the car to a stop when the throttle was pinned electronically. In all cases, car was able to come to a complete stop - some not much further than if the throttle was in idle. Only cases where it became a problem was when the test driver jumped from brake to throttle repeatedly. That case, it bleed off the vacuum assist quickly, took a significant amount of force on the brake pedal to stop the car (think no power assist, all drum brakes). Some people are just not used to using that much force in a power assisted vehicle.

Share this post


Link to post
Share on other sites

Hey Fish this is good stuff!!!! To bad its on the car model I want to buy....LOL.

 

I mainly do pcb design now...top level embedded is best left to the young whiz kids...to old to be that now. But the damn tin whisker stuff has made my life a lot tougher. We battled that back some years ago when

doing a design for GM that was potted in epoxy...what a nightmare. Right after I posted the above I said

to my wife...."remember...Toy has its butt sticking out a lot more with their Q rep than other car companies. So when something like this pops up everyone goes more over board then usual".

 

I was chuckling at the holding the brakes and gas at the same time....used to do that to do awesome burnouts. One thing I was wondering if anyone tested out....is the slamming the brakes will stop the car. WHat I wonder if when guys testing this....did they first hit the gas to let the car get moving...like a horrified driver would...then slam the brakes on? Or did they hold the brakes then gun it?

 

I saw some of these videos of the guy on the highway at 100mph saying he couldn't stop it nor shift it into neutral. I accidently did that with our Honda....hitting the shifter and into N it went....but I wasn't accelerating....just coasting. Wonder if under heavy load of accelerating if the driver cant shift it into N?

 

I found one article tonight on this engineer whose wife had her Corolla hit a park car.

 

http://abcnews.go.com/Business/wireStory/safety-agency-studying-toyota-acceleration-problem-25833671

 

I'm still going to keep looking at them. But I still have the issue of this model kills my right shin which is a big bummer. I thought the tele steering wheel would help but I still feel like something is off

with the pedal location vs our Honda or even the Ford. My buddy has the same issue with his Matrix. But that and this possible throttle issue has me holding back abit.

 

Thanks for the excellent info!

Edited by cirrus

Share this post


Link to post
Share on other sites

Sweet - haven't done board level design in some time! Software modeling and PCB layout tools change all the time - right now, we are using Altium Designer for board layouts and simulations. I'm involved more in the high level work - mostly programming and algorithm development. Funny you mentioned the issues you've seen with tin whiskers in your work. We've come about full circle there - back when the vacuum tubes were popular, tin whiskers were an issue - now with RoHS directive - refocusing a lot of energy chasing those down. We run into the same stuff with our equipment, mostly custom sensors/electronics for marine applications. Even with conformal coatings on the boards and fully potting them in some pretty crazy epoxies - you still have to be mindful about tin whiskers. Lots of headaches for the PCB layout guys - have to fight the mechanical guys for footprint and overall volume, but they need as flexibility in parts layouts to minimize potential failure modes.

 

Yeah all depends on the car and the driver - once stuff happens, get that adrenaline going - everything seems to take forever to work. Hauling down the road at 90+ MPH, even if the car goes into neutral - it will coast a good distance if you don't touch the brakes, even for a vehicle like a Hummer.

 

When this SUA story was still pretty hot in the media - I've coached my wife on what to do in the event of SUA. Sort of like muscle memory - just practice it a number of times and it will pop up when you need it. I still have to fight pumping the brakes during hard braking - since I'm used to car that don't have ABS, uses drums all around + no power assist. We've also tested a few what if scenarios on our Matrix - full on throttle, shift into neutral - car rev's immediately bounce off the rev limiter and car went into neutral. Even tried to shift into park at highway speeds, transaxle defaulted to neutral instead (don't try that in an 80's or earlier model year car though - don't ask how I know).

 

I know in the cases of testing if the brakes hold the car - they pin the throttle down (WOT), get the car up to speed, then bring the car down to a stop with the brakes only, throttle still pinned. They do multiple passes as quickly as possible to try and really cook the brakes. Car still slows down and eventually stops. Unless the car has a wicked amount of power compared to the brakes - the car always slowed or stopped to a very safe speed.

 

But I can see a panicked driver alternately swapping between the gas and brake in an attempt to change something. Vacuum assist will drop down to a level where even a pretty stout fella would have to press pretty hard on the brakes - some SAE papers showed in those cases, you need a stupid amount of pedal force, something like 125lbs or 175lbs of force. I know my wife probably couldn't put enough force in that case - elderly people and very young or inexperienced would like have no chance.

Share this post


Link to post
Share on other sites

Oh man...why couldn't you have said Orcad 16.6....my latest dragon to slay!!! Its been slaying me though.Its totally different than my order version....they no longer use terms like tracks...copper...footprints....they changed them to clines....etch....and symbols. And you should see the layers of menus and submenus....and the terms they use at times make no sense whatsoever. We had an issue today that I finally solved but if their tech didn't tell me we'd have NEVER found it.

 

I was laughing so hard at one demo...several engineers already used it for months and this one guy finally melted down over how hard it was to change the silk text. He yells..."I didn't know I needed two monitors....four books and three courses on moving silkscreen...that in the old package took me one mouse click!!!" I wasn't laughing later when I then blew a gasket trying to make DXF's and found out in the end I wasn't clicking a box that had no meaning whatsoever. The package is very powerful....and I like a lot of what it can do...but it irrates me to no end how bloated it is with some things. Even trying to measure somthing fast is a pia. It was written by database guys....and it looks it.

Right now I cant get it to put thruhole testpoints my boss likes to use....I can add them to bottom of the pcb..but not the top.

 

My wife would never think fast enough to stop a SUA....which is why I hoped they added in that Smart Stop...which if they did for sure in the 2014's maybe I'll go back to looking at those. Our local dealer was giving me a great deal on a 2015. My wife also thinks the motor will explode. I told her it will ping off the rev limiter....let it....then shut it off once you stop. At worse the motor seizes but its not going to explode like a NHRA funnycar.

Edited by cirrus

Share this post


Link to post
Share on other sites

Never fails....just as we were getting ready to purchase another Corolla (used 2011-2013) I see on the news today there is issue again with the above post of acceleration issues. We love our 2005 LE....best car we've owned and running strong, looking great at 155K. But my wife is horrified of any acceleration issues so now wants us to look at something else. Even she hates the interior of the Civic so that's probably out....Fords have tranny issues.

 

Fish...Dom....anyone...know why they are saying its 2006-2010's Corollas??? Are those years the only ones with complaints? Could this spread to 2011's and later??

 

What the heck is going on again?!!

 

For me, inching up at a stoplight took some practice. A little too much throttle, even when I feather it, can make my '09 S jump. Was inching up at a light once, and in a flash, I was heading right for the car in front of me. Let me tell you, that was scary--the kind of scary that makes a person kind of lose it a little. The experience was quite a jolt, I can tell you. So now I'm extra extra careful when applying just a little throttle.

 

Perhaps there is some calibration with the fly-by-wire acceleration system that's causing it. Don't know. Am also unsure if this is the problem others experience. As an aside, I've yet to experience the issue in my wife's '09 Focus SEL, which I drive every now and again.

Share this post


Link to post
Share on other sites

Well speaking of this....we just got a check for $30 from Toyota about the SUA issue. I didn't think our 2005 was part of that stuff??? And I usually opt out of this stuff...did I miss that letter asking what I wanted to do??

Share this post


Link to post
Share on other sites
Guest
You are commenting as a guest. If you have an account, please sign in.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×