NHTSA-NASA study of Toyota vehicles finds no electronic causes of unintended acceleration

I have said many times that when it comes to safety, the Department of Transportation will not take a back seat to anyone. As long as I am on the job, the safety of the American public will be my top priority.

Last year, in service of this commitment--and at the request of Congress’ --we launched an unprecedented study into unintended acceleration in Toyota automobiles. We asked a straightforward question: Could electronic systems or electromagnetic interference cause unintended acceleration in Toyota vehicles?

Seated from left to right: Michael Kirsch of NASA, NHTSA Dep. Admin. Ron Medford, and NHTSA Admin. David Strickland

To help answer this question, we enlisted the top engineers at NASA with expertise in computer controlled electronic systems, electromagnetic interference and software integrity. They worked shoulder to shoulder with the best minds in auto safety at the National Traffic Highway Safety Administration (NHTSA) to help get to the bottom of any electronic causes of unintended acceleration.

And today we have heard clearly and affirmatively that NHTSA, America’s traffic safety organization, was right all along.

NASA's Michael Kirsch explains the thorough testing of Toyota vehicles

NASA's team found no electronic flaws in Toyota vehicles capable of producing the large throttle openings required to create dangerous unintended acceleration incidents.

NHTSA has already identified the only two known real-world causes of high-speed unintended acceleration in Toyotas, and Toyota has taken action to correct these defects. The first defect involved a design flaw that allowed drivers’ gas pedals to become entrapped by floor mats while their vehicles were in motion. The second defect, so-called “sticky pedals” made some Toyota accelerators too slow to release.

Today's results were the product of one of the most exhaustive, thorough, and intensive research efforts ever undertaken.

NASA engineers pored over more than 280,000 lines of software code looking for potential flaws that could initiate an unintended acceleration incident. Alongside NHTSA, they bombarded vehicles with electro-magnetic radiation to see whether it could make electronics systems cause the cars they control to gain speed.

And today, their verdict is in. There is no electronic cause behind dangerous unintended acceleration incidents in Toyotas.

Now, this doesn't mean that we haven't asked Toyota to accept responsibility for known mechanical causes of unintended acceleration. We have.

Toyota has issued recalls and paid for repairs on nearly 8 million cars and trucks for the two defects NHTSA identified. And Toyota paid the maximum civil penalties as the result of NHTSA investigations into whether the company reported these safety defects in a sufficiently timely manner.

I want America to know that NHTSA remains a vigilant safety agency. On the heels of this investigation, we will continue to do what DOT has always done--work around the clock to keep American drivers and passengers safe.

NHTSA Administrator David Strickland emphasizes safety

We will research placement and design of vehicle accelerator and brake pedals, as well as driver usage of pedals, to determine whether we can reduce pedal misapplication. We will begin broad research on the reliability and security of electronic control systems.

And, we are considering proposing rules by the end of 2011 requiring brake override systems, standardized keyless ignition systems, and event data recorders in all passenger vehicles.

I am deeply grateful to the dedicated safety professionals at NASA and NHTSA who conducted this study with extraordinary thoroughness, immense skill, unwavering attention, and absolute integrity. It was an enormous task, but they pursued their work with care.

Comments

[Andrew Haliburton]

The findings of this study are interesting, but this doesn't begin to address the very real unintended acceleration in a Corolla, experienced many times (once, simultaneously by two engineers and a Toyota mechanic) in South Africa, November 2009.

I have no beef with Toyota, but I've yet to see an acceptable explanation for what we experienced, as I described on the New York Times web site on December 8, 2009:
"In November 2009, I and three other adults experienced this “possessed” behavior in a rented manual Corolla (model 2008?). I witnessed three drivers experience the phenomenon, one of whom was a qualified Toyota mechanic. He didn’t believe our story after his diagnostics computer reported no anomalies, so he drove the car with us along as passengers. It was some consolation that he too experienced it. It generally occurred when the car was travelling over 100 km/h, with more than 50% throttle. Because the car was accelerating of its own accord under full throttle, the effectiveness of the brakes is severely reduced. It is the frightening part. When the gear lever was placed in neutral, the revs climbed to 6,500 and held there. The ignition key was then switched off and back on again to kill the engine. When in heavier traffic, a couple of times, the transmission was crash-changed into third gear to try to help slow the vehicle. The rental company dismissed our story; assuring us that the problem we experienced was due to a bunched floor mat (we had placed the floor mat in the trunk/boot of the car earlier so as to eliminate this variable). This experience had nothing to do with mats, carpeting or anything else in the cabin of the vehicle."

[CruxFiveTen]

This was a crazy witch hunt at that time, to somehow ruin and slow down the Toyota juggernaut. The media and politicians quickly jumped on the bandwagon also. Its pretty obvious by now all this was done to benefit the 'people' owned government motors and other struggling domestics brands. Pretty sad and pathetic.

[John moore]

I certainly hope you use an equal amount of press to explain this was a false rumour as you did when you hurt the auto makers reputation. They are a good company who deserves vindication. Many american who work for toyota usa lost considerable income by the secrataries glib comments. Toyota is a great american corporate citizen.

[Kevin Seals]

I feel that Mr. LaHood owes Toyota a public apology for the hysteria he created around this issue. He damaged a good company's name without proof of electronic problems. He should be just as forceful in stating that they were cleared off all wrong doing concerning the electronics as he was quick to condemn them.

Sincerely,
Kevin Seals

[Paul]

I sure hope that your findings get the attention that your accusations did! I know that they won't but you cost a lot of hard working Americans income - There are a lot of folks in this country that are employed by Toyota their dealers... manufacturs... suppliers... etc.. etc.. I work on the front line that was affected - I sell Toyotas - and your "unprecedented study" was far too strong an action to have taken. I really hope we hear some sort of Official appology for your actions!

Paul -
6 Year Toyota Salesman.

[Bob]

My Ford F150 has the same uncontrolled acceleration problem and no one seems to care....the dealer nor the NHTSA...I CAN MAKE IT HAPPEN and no one wants to see it! Do they care...of course not.

[Steve Winkler]

To Secretary LaHood:

The Toyota study is WRONG!
I own two Prius' and both exhibit
electronic irregularities that the best
mechanic I've ever met in my 70 years on earth
(he works for Toyota as a troubleshooter) cannot
explain.
When the battery(s)is/are low (there are 8) the cars
behave 'strangely".......example: if I put it in "drive" it MIGHT go into reverse or vice-versa. It is not me.
The Toyota people have seen it many times on bith my vehicles but can't explain it or offer a fix.
Being that the throttle is also electronically
controlled why can't the above be the cause of the
sudden acceleration problem also.
The cars given to NASA-NTSB probably ahd no battery
defects.

Steve Winkler
Stevew5234@yahoo.com
(516) 356-5234

[Rock]

This is why are country is in the shape it is. One of our own officials telling the country he encouraged his daughter to go and buy that Toyota minivan she was wondering about. Its disgusting, talk about shoving a knife in American auto workers and investors back. Our own official, telling the country in other words don't even consider going American take your chances with import instead. If he worked for me I would fire him. Thanks alot mister trans. Secretary.

[Norm Talsoe]

The Driver side of the Toyota SUA Story
(that rarely if ever gets reported)

Following is a summary of the SUA experiences I have had between 2004 and 2006 on a Lexus LS400. I am sick and tired of hearing the constant mantra that the driver is at fault. Finally some justice was served when Lee was released from prison as a result of the legal system finally listening to the driver experience and actually believed what they heard to the extent that reasonable doubt could be established. There is an overwhelming flow of self serving and unintelligent comments from Toyota, the media and self proclaimed experts who have not experienced an SUA. The worst is the assumption that because Toyota has not been able to replicate the problem “It must be the drivers fault.” I am sure that everyone knows the definition of “assume.” The burden of proof should be on Toyota to prove that they can capture an SUA event that includes a wide open throttle, coupled with sensing a braking or accelerator action. None of these “driver did it” statements reflect a rudimentary knowledge of statistics or the difficulties of troubleshooting problems caused by intermittent performance.

I can make this statement because I have lived through 6 SUA incidents between 2004 and 2006. I have written many times to various people, including Jim Lentz of Toyota, concerning this problem to no avail. Toyota knows perfectly well what is happening but chooses not to acknowledge the problem rather than pay the huge legal bills that would come from the many lawsuits. Furthermore I am an electrical engineer that has spent over 20 years in chasing similar intermittent problems in the computer industry. The SUA's are a statistical problem that requires some rudimentary knowledge of statistics and signal to noise theory to solve. Various pundits, pointing at driver blame, have no such knowledge or appreciation and have not researched the subject to the extent necessary to make an informed opinion.

Problems like this are rare and may happen once every 1000 hours or even months or years. Who can predict a lightening strike which is a good analogy? In my case, the first series of 3 incidents in 2004 were about 300 hours apart. The second in 2006 were about the same occurrence separation. Toyota told me the same thing as all other victims have heard ---- there was no evidence of the occurrence ---- incidentally I told them there would be no record. Why? Because in attempting to successfully chase intermittents, with zero predictability, you must have incorporated in the car's design, "sensing" that would, for instance, look for a condition of open throttle and simultaneous braking application and no accelerator application. Since Toyota couldn’t detect an occurrence just proves that they haven’t designed the sensing into the electronics to do it. Toyota should have to prove by showing test data that they could capture the condition if it occurred. Procedurally they should force that condition into their computer system and show that they can capture the occurrence. It is ridiculous to "assume" that because there was no such evidence that the driver must be at fault. This is analogous to blaming the victim of a lightening strike for the fact they got hit.

This should have been challenged by the legal team in all these cases -- it wasn't -- they were incompetent. In the case of the computer I worked on (Univac 1107) in the early '60's at least we knew when a failure happened by the parity checking system that was active. Even then, when we knew we had failures, it took 6-7 months to correct all the causes because we couldn't make them repeat until we isolated those causes by using troubleshooting and failure analysis techniques. There were numerous noise sources that had to be eliminated (conducted noise, radiated noise, ground noise, etc). The worst one was sensitivity of the storage drum to temperature variations when air conditioning was turned on and off. That took close to 7 months to find. These were all sources that were outside the anticipated problems expected in doing the original computer design. During that year, in trying to give birth to the 1107, all of management was on a 24 hour day 7 days a week to solve this problem. Toyota should invoke such an effort and look “outside of the box” in trying to explain what is happening. But the first thing they MUST DO is prove they can capture the occurrence because it is happening. They just haven't figured out how to sense the fact that it occurs.

Like all the descriptions by other victims, I had to put both feet on the brake and brace by pulling on the steering wheel, to try and keep it in check. It leapt forward 3 times (in about 3 seconds) before I could get the shift into neutral. In all incidents I stopped about 6" to a foot from the car in front of me (obviously my feet were on the brake to stop --- not the accelerator). In my case, when I shifted back into gear, it no longer had the symptoms. Toyota diagnostics, even calling in the experts from Chicago, showed that nothing happened.

Moreover, in the history of these events, there is plenty of evidence that SUA's were real if anyone actually did their home work. Not counting my incident, there were other cases where two different owners of the same car had similar SUA incidents. Both discontinued driving that car. Again Toyota could not replicate the problem. In another occurrence a driver with an active SUA incident drove the car into a Toyota dealership by alternating between the car in neutral and full throttle. He pulled into the dealership, put it in neutral and the engine was running at full throttle. The dealer tech verified that the floor mat was removed but was unable to stop the wide open throttle and was forced to shut the vehicle off. The same car brought in to the dealer, for a previous incident, revealed no problems when diagnostics were run on the computer. This occurred at the dealership and they claimed that they didn't have a problem. Give me a break! Toyota offered to replace the accelerator and throttle assembly for this “nonproblem.”

Yet again, there was another incident in San Diego where a family got killed in a loaner car. The week before the previous user of that car had a similar incident that, luckily, didn't result in death. An explanation for all of these could be that the computer controlling the system "hangs up." Who hasn't experienced the typical "Blue Screen" error where the computer hangs and has to be rebooted to recover? If that happens the computer clock stops being active and any data that occurs during that time will not be recorded. I understand that even fighter planes that are now all fly by wire systems have a manual override to cope with such computer errors.

The below report offers more details.


Sincerely,
Norm Talsoe

MY DETAILED SUA Experience

Being a survivor of 6 SUA incidents in a 2000 LS400 I personally know that Toyota has a Sudden Unintended Acceleration (SUA) electronic throttle failure problem. There may be several other causes for SUA’s, but among them has to be the throttle failure. Toyota’s defense: they have never found any evidence of an electronic failure so it has to be the drivers fault.

My SUA experience proves to me that they have not yet been able to capture the failure events with their diagnostics. That being true, they can’t even begin to solve a problem they haven’t been able to see.

Failure evidence comes from the complaint statistics that have been compiled over the years. In one case, the original owner of an LS400, Peter Boddaert, had 3 episodes, sold his car and the second owner, Mark Pinnock, also experienced 3 incidents with the same car. Pinnock had to discontinue driving it. This fact, coupled with my own experience, substantiate that Toyota has an electronic throttle problem.

Further proof: In another bizarre example a driver began to experience an SUA event with his Avalon but was able to reach a dealer where, with the gear in neutral, the engine continued to operate at full throttle. The dealer tech verified that the floor mat was removed but was unable to stop the wide open throttle and was forced to shut the vehicle off. The same car brought in to the dealer, for a previous incident, revealed no problems when diagnostics were run on the computer. The dealer eventually offered to replace the throttle body, accelerator pedal and associated sensors free of charge to the driver after the second incident. An interesting solution for a problem Toyota claims doesn’t exist.

NHTSA never pursued the requests for investigation.

How Toyota can continue to claim they have no problem with the electronic throttle is beyond me. The above examples clearly show that they, “indeed”, have a problem.

What the Symptoms Tell Us

My 6 SUA incidents with a 2000 Lexus LS400 occurred between 2004 and 2006. The symptoms were: starting from a stop with my foot on the brake, as I removed my foot but before getting to the accelerator, the car jumped to, what felt like, full throttle. Since, before releasing the brake, the engine was idling normally it suggests the accelerator position sensors were delivering the proper signal to the Electronic Control Module

(ECM). After releasing the brake the engine went to full throttle and tried to leap forward causing me to put both feet on the brake. At this point it is clear that the ECM CPU’s were no longer responding to the accelerator which hadn’t been touched after releasing the brake. The position sensors should still be sending an idle message to the CPU. It appears that releasing the brake sent some unknown signal to the CPU that caused it to “latch up” or freeze (in a full throttle state). The car leapt forward 3 times, moving about 1 foot each time before I was able to shift to neutral. In all cases, luckily, I was able to stop just before hitting whatever was in front of me. The incidents each took only about 3-4 seconds. Once in neutral the car again idled normally because the CPU again was tied to the accelerator sensors that still were in the idle position.

I would speculate that when the EMC CPU was frozen it could not accept inputs from the sensors i.e., the system was frozen during the time any message was trying to be sent. Once the system went back to normal the diagnostics showed everything ok since the frozen CPU had not received any failure message. Guess what? “No Trouble Found”

The point to be made here is that there has to be a simple redundant system outside the electronic throttle that was immune to whatever froze it. It could interrogate the electronic throttle system, determine it was frozen and be able to release it. However, this may be easier said then done.

When our home computers freeze, we are forced to reboot. When this happens in a fighter plane I understand that there is an emergency button that can be pressed to allow manual control until the fly-by-wire system can be reengaged. Perhaps the equivalent for this problem is the brake override solution. But a concern among safety experts is that the brake override software, which has been described as a final solution to the problem of unintended acceleration (SUA), may cause more problems by adding a new layer of software to the system. "These fixes are not dealing with the root causes of the problem," said Sean Kane, president of Safety Research and Strategies Inc. Besides if the brake override solution relies on the CPU that gets frozen what assurance is there that it will work?

In trying to troubleshoot the electronic throttle it should be possible to cycle the logic inputs for the throttle system through all possible state combinations to see if a frozen open throttle could be invoked at a particular input combination. If that condition could
be replicated it would then be possible to work toward a solution. I don’t know if this would work for a potential software bug. Ideally this should be done on the throttle system of a known SUA offender. The culprit looks to be the CPU used by the ECM since the SUA events have occurred for virtually all of the automobile industry. Design differences by different manufacturers would make the throttle more or less sensitive to triggering an SUA event. The evidence sits in all of our homes in the form of a home computer. Who hasn’t experienced a frozen system?

A Statistical Problem

The SUA events rarely occur, being maybe only .005% or less of all known failures. Because it is so rare, it is equally difficult to make sure that when a SUA happens, you can capture the fact that it did. The above explanation is the only one I can think of that agrees with the SUA symptoms. Even when a car having the problem is evaluated it would be very difficult to find the exact failure mode that causes the runaway full throttle. In a normal production car I don’t think you would have a prayer.

I think Toyota is between a rock and a hard place. They know they have a problem, they don’t know the cause, can’t duplicate it and they can’t admit it. If they did they would immediately be guilty in all the pending law suits. Their best out is to implement the brake-override. They will continue to deny any electronic problem because it would be cheaper than admitting it. If they find it in the future, they will correct it and in the meantime, hopefully, the brake override will hide the problem.

Incidently I traded my SUA LS400 for a Lexus LS430 after getting a somewhat reasonable deal (I bet on the low probaility of SUA to not repeat my problem). It is the best car I have owned so far so I have no axe to grind with Toyota.

However, they're lying through their teeth in saying they don't have a electronic throttle problem. I will take a lie detector test ---- will they. They are either lying or they don't know they have a problem because with the low probability they haven't caught it yet.

It would require capturing an SUA offending automobile that you could test exhaustively --- even then the probability of capturing the event would be difficult. It's the nature of the "beast." Intermittents don't predictively repeat.

N. Talsoe

[Mosmosnyc]

Are you returning the fines Toyota paid which they shouldn't have had at the first place?

[Nick]

We use Toyota vehicles in our fleet. thank you for sharing safety concerns as it makes us more aware.

[Steve]

Thanks for the info.

[John]

I have never thought that newer vehicles could have "unintended acceleration" as an issue. Could this happen only when cruise control is on? Are there any other vehicles that have had this happen, which caused this investigation to occur?

[KeyResumeHelp]

I also have read that in March 2010, NHTSA enlisted the support of NASA in analyzing the Toyota electronic throttle control (ETC) system to determine whether it contained any vulnerabilities that might realistically be expected to produce unintended acceleration (UA) in a consumer’s use of those vehicles. NASA did not find an electronic cause of large throttle openings that can result in UA incidents. NHTSA did not find a vehicle-based cause of those incidents in addition to those causes already addressed by Toyota recalls.

This report presents NHTSA's studies and findings concerning UA in vehicles manufactured by Toyota. It should be read in conjunction with the report issued by NASA concerning the ETC system in Toyota vehicles.