Why Toyota Has a Whisker Across its Bumper

When you’ve shelled out big bucks for a message, the dissenters have to be squashed – and fast. Yesterday, Toyota public relations rapid response team tried to bring the Toyota Unintended Acceleration (UA) problem back into its multi-million-dollar corral at the There’s Nothing to See Here, Folks Ranch.

Mike Michels, Vice President for External Communications of Toyota Motor Sales, U.S.A., wrote an editorial, in response to a well-reported and written story by the Huffington Post’s Sharon Silke Carty about one of the most significant physical findings of the NASA Engineering Safety Center’s (NESC) study of the electronic causes of unintended acceleration in Toyota vehicles: tin whiskers. Tin whiskers are crystalline structures that emanate from tin and other alloys used as solder on printed circuit boards. These nearly microscopic metal hairs can bridge circuits, leading to electrical shorts and significant malfunctions. They have caused failures at nuclear power plants and medical devices and downed satellites. While we don’t believe that they are the cause of UA in all Toyota vehicles. Clearly, tin whiskers have been strongly implicated as a cause of UA in some Toyota vehicles.

This story touched off an interesting and intelligent discussion among readers, generating more than a thousand responses. While there were a few of the “loose nut behind the wheel” and “evil trial lawyers” variety, the majority of comments appeared to come from readers with technical backgrounds who were well-versed in the headaches caused by tin whiskers, a longstanding issue in the electronics industry.

Mr. Michels effort to beat back a challenge to Toyota’s preferred narrative, however, is rife with mischaracterizations and falsehoods.

Mr. Michels says that the engineers at the National Aeronautics and Safety Administration (NASA) have been “clear and unequivocal” in their conclusions. They have not. The February report, Technical Assessment of Toyota Electronic Throttle Control (ETC) Systems and Technical Support to the National Highway Traffic Safety Administration on the Reported Toyota Motor Corporation Unintended Acceleration Investigation, written by the NASA Engineering Safety Center (NESC) actually said:

“Due to system complexity which will be described and the many possible electronic software and hardware systems interactions it is not realistic to prove that the ETCSi cannot cause UAs. Today’s vehicles are sufficiently complex that no reasonable amount of analysis or testing can prove electronics and software have no errors. Therefore, absence of proof that the ETCSi caused a UA does not vindicate the system.”

Mr. Michels said that there are no real-world scenarios in which Toyota electronics can cause unintended acceleration. That is not true. The NESC team, which found tin whiskers in every potentiometer pedal it examined in a very small sample, studied one from a Camry that had experienced unintended accelerations. The owner described the pedal as “jumpy” and the car as “completely undriveable.”

Further, in May two NHTSA engineers witnessed, videotaped and captured data from a 2003 Prius that had multiple UA events in their presence. Yesterday, the agency conceded that there was no evidence that these UA events were linked to the” known causes” of floor mats, sticking accelerator pedals or driver error. This suggests that the culprit is to be found in the software or electronics.

Mr. Michels says that the National Academies of Sciences laid to rest “this discredited theory,” concluding that all the data available indicated that there was no electronic or software problem in Toyota vehicles and that NHTSA was justified in closing its investigation.

The NAS panel did not actually examine the tin whiskers phenomenon. It devoted one paragraph in a 158-page report to the subject. As for clearing Toyota, the NAS report actually said:

“The absence of evidence is not evidence of absence.”

Mr. Michels also cited the affirming pronouncements of “respected independent experts,” such as Edmunds.com and U.S. Secretary of Transportation Ray LaHood. Edmund’s.com sells cars. Ray LaHood is a politician who taught high school social studies before winning public office. Neither are automotive electronics experts.

Mr. Michels says that Toyota’s systems are designed to reduce the risk that tin whiskers will form in the first place and that “multiple robust failsafe systems” detect faults, illuminate the malfunction indicator light and put the vehicle into ‘limp home’ mode.

Neither is true.

In August, some actual electronics experts from the University of Maryland’s Center for Advanced Life Cycle Engineering (CALCE) published an analysis of the potential for tin whisker growth in Toyota vehicles. The scientists performed a physical analysis of an engine control system from a 2005 Camry XLE, V-6 and an accelerator pedal assembly from a defunct 2002 Camry. The 2005 engine control system included the ECM, an accelerator pedal unit, throttle body, electrical connectors and electrical connecting cables. The tear-down of the accelerator pedal position sensors (APPS) in both Camrys revealed tin whisker formations. In addition, the CALCE researchers found the potential for tin whisker formation in the ECM, which contained surface mount electronic devices connected with tin-lead solder to a multilayer PCB; interconnect terminals of the perimeter leaded devices plated with tin. And tin plating on terminal pins of the edge connections. The CALCE scientists concluded:

“In our analysis, a significant number of tin whiskers were found. Using the calceWhiskerRiskCalculator (CALCE Tin Whisker Risk Calculator, 2005) to assess the failure risk posed by observed tin whisker formation on the conductor pairs, it was determined that the potential for a tin whisker shorting failure was 140/1 million. Considering the number of vehicles on the road, it is expected that this would present a significant safety hazard.”

Other automotive electronics experts, such as David Gilbert at Southern Illinois University have demonstrated that Toyota’s fail-safe strategy is not robust and under certain circumstances fails to detect faults that can lead to open throttle.  In an August 2010 recall intended to correct stalling in 2005-2008 Corolla and Corolla Matrix vehicles, Toyota submitted field technical reports on the problem, many of which noted that diagnostic trouble codes were not set, even when the technician could duplicate the problem. Toyota’s fault-detection system does not always function properly and does fail to detect abnormalities and set trouble codes.

Mr. Michels asks: “Why, then, is Toyota continuing to be subjected to unwarranted speculation in the news media about an issue that has long since been put to bed?”

Well, it’s not due to the fanciful conjecture of plaintiff’s lawyers and its paid consultants or a frenzy of non-news news. It’s because Toyota’s customers continue to report unintended acceleration incidents that cannot be credibly blamed on floor mats, driver error or sticky pedals. NHTSA alone fielded 330 complaints from Toyota owners who experienced a UA event in 2011. Some 247 customers have complained to the agency about events that occurred after they had their floor mats and accelerator pedals remedied through the recalls.

Toyota’s problem is that it has treated unintended acceleration in its vehicles as a public relations dilemma, rather than a technical issue.

If Toyota wants the public to stop discussing Unintended Acceleration in its cars, why don’t they just fix them?