NASA scientists to examine sudden acceleration

The Courier-Journal: "The Obama administration said Tuesday it will intensify its probe into sudden acceleration complaints from Toyota vehicles, bringing in NASA scientists to examine how Toyota's electronic controls could be affected by electromagnetic radiation, software faults and cosmic rays."

A separate National Academy of Sciences study will examine the full range of sudden acceleration issues — including human error — in all makes of cars and trucks, U.S. Transportation Secretary Ray LaHood told the Detroit Free Press.

He said the move comes even as federal auto safety officials have found no electronic faults in Toyota vehicles.

“We haven't been able to find anything wrong with the electronics, but I've made a commitment to Congress, Toyota and other car owners that we would find the very best experts we could to look into this,” LaHood told the Free Press.

The Free Press first reported earlier this month that the National Highway Traffic Safety Administration was considering the potential impact of cosmic rays on electronic systems as a cause of the sudden acceleration.

LaHood also asked the Department of Transportation's inspector general, the agency's independent investigator, to review whether NHTSA mishandled complaints of sudden acceleration in Toyotas during probes dating back to 2003.

The moves come as the National Highway Traffic Safety Administration already has three separate probes underway into whether the world's largest automaker withheld safety information from the agency before announcing recalls in January that now cover 13 models and 5.6 million vehicles in the United States.

LaHood said the National Academy of Sciences will conduct the broad study into sudden acceleration and electronic controls, including all possible sources from human error to electromagnetic interference. The study, which should take about 15 months, should produce recommendations for NHTSA to handle future complaints.

The academy will probe “not just Toyota, but all vehicles, and not just sudden acceleration, but all electronic controls across the industry,” LaHood said.

Safety officials look into Toyota Corolla stalling issue

USATODAY.com: "Government safety officials are probing a flaw that could cause popular Toyota Corolla compacts to stall, a problem that Toyota says is likely to affect only a tiny number of cars. Although some owners have said cars stalled in intersections or on highways, Toyota says the issue shouldn't be considered a safety problem.

Toyota has known of the problem with the engine control module, or ECM, for at least 21/2 years, according to National Highway Traffic Safety Administration files. In September 2007, Toyota issued a bulletin to dealers, NHTSA says, telling them to replace the ECM with an improved model to fix complaints in 2005 through 2007 Corolla and similar Matrix small cars. That's about 1.2 million vehicles."

Those technical service bulletins (TSBs), issued by the hundreds every year by all automakers, often authorize a dealer to make a free repair if a customer complains about the specific problem, or to fix it when the vehicle is in for other service. But they don't guarantee a free repair, nor are owners necessarily alerted to the potential problem.

In a March 2 letter to NHTSA, Toyota said it "does not believe that the alleged defect creates an unreasonable risk to motor vehicle safety." The automaker said the flaw, due to faulty parts from suppliers, affects 0.8% of the vehicles. Toyota acknowledged that some drivers would be "inconvenienced" by stalling, but said the alternative is allowing the engine to run during the fault and possibly fail or catch fire.

That letter was in response to NHTSA's query as part of a preliminary evaluation, the first of three steps that can result in a government-ordered recall, though that's rare.

The letter came days after top Toyota officials promised two House investigating committees that it was beginning a new era and would aggressively tackle safety concerns.

Toyota has recalled 5.4 million U.S. vehicles because floor mats can jam gas pedals open, and 2.3 million because a defect might cause gas pedals to stick open. There are reports of 52 deaths linked to unintended Toyota acceleration, though NHTSA says it has not verified all those reports.

That Toyota didn't recall the Corollas "doesn't suggest a car company that has a whole new set of processes for dealing with safety," says Jeremy Anwyl, CEO of auto research site Edmunds.com: "If I'm pulling through an intersection and the car dies and could be hit, that's a safety problem."

Toyota Investigating Corolla and Matrix Engine Computer in Stalling Cases

Motor Trend Magazine: "Back in December, just as the Toyota recall crisis was really heating up, we reported that the Toyota Corolla and Matrix were being investigated for an engine stalling problem. Today, Toyota has revealed that a possible cause has been found and it has contacted the National Highway Traffic Safety Administration to further the investigation."

"Toyota does not believe that the alleged defect creates an unreasonable risk to motor vehicle safety," Chris Santucci, Toyota's regulatory affairs manager, wrote in a letter to NHTSA.

In the letter, Toyota identified the Engine Control Unit, the computer that runs the engine, as the culprit in the sudden and random engine stalls. Toyota believes that a crack in a soldered joint inside the computer could be to blame, or possibly an electrical short. Either problem could cause the engine to shut down or fail to start. According to the letter, Toyota believes that an engine stall is the safest outcome of such a failure.

NHTSA began investigating the problem in late November after receiving 26 complaints of sudden engine stalls in the Corolla and Matrix models, which are essentially the same under the skin. The problem only affects the four-cylinder engine and appears to occur at random. Nearly half of the reported cases occurred while driving, but no injuries or deaths have been reported. A replacement ECU appears to be all that is necessary to alleviate the problem.

While the exact cause of the stalling hasn't been pinpointed, Toyota said in the letter that it would like to meet with NHTSA to delve deeper into the issue. No recall has been announced yet, but Toyota says in the letter that the problem could potentially affect 1.19 million Matrix and Corolla models from the 2005, 2006 and 2007 model years. Some Corolla and Matrix models are already under recall for faulty floor mats and sticking accelerator pedals. Toyota has not said if this ECU problem is in any way related to the sudden unintended acceleration issue, but it doesn't appear to be since it has the opposite effect.

Source: Automotive News (Subscription required)

Lack of Care in Reporting can Mislead Greatly Re Tin Whiskers

Dr. Lasky's Blog : "To be fair and thorough myself, I want to point out two things:

Several media, not just Circuitnet, picked up the original story regarding tin whiskers as a possible cause of Toyota’s problems. The original article appears here: http://www.techeye.net/chips/electronic-tin-whiskers-may-be-behind-toyota-recalls

2.Temporarily ignoring the poor science at the root of the “claim”, I maintain that editing out the key phrase “may be” from the original story contributes to an increased misunderstanding of the actual facts."

I know and respect the team at Circuitnet, but it seems like they made a pretty serious goof today. Their top story today had headlines stating: "Tin Whiskers Behind Toyota Recall." The link to this story takes us an article with the title "Electronic Tin Whiskers may be behind Toyota recalls."

So we start with a headline telling us that tin whiskers are behind the recall and when we go to the main article we see that tin whiskers may be behind the recalls. The person that the article is quoting is Keith Armstrong an EMI (electromagnetic interference) expert. In this article Armstrong states that EMI may be the culprit in Toyota brake malfunction.

From what I see in the article, Armstrong has no data, and has not looked at a failed Toyota brake system. He is just arguing that EMI may be the culprit. Who knows?

Armstrong is then quoted as saying that tin whiskers, in the lead-free solder, may be to blame for the recalls and he then references work by John Barnes. Barnes' exhaustive summary has nothing to say about tin whiskers in Toyota braking systems, just a bit about tin whiskers in general, in the over 1,000 pages about lead-free issues. Armstrong is then quoted as saying that the tin whisker problem, "has caused serious problems in the computer industry previously." The article at this link is dated 12 November 2002 and is simply a call for papers on tin whiskers at a conference. Strong suggestions for having no data!

I don't want to minimize the concern for tin whiskers, but the headline in Circuitnet and the article it links to have nothing factual to do with tin whiskers in the Toyota recall situation. Given the seriousness of this situation, this misleading reporting is troubling indeed.

Cheers,

Dr. Ron

PS: One commenter to the main article points out that Toyota uses leaded solder in the brake electronics. I don't know if this is true, but given the RoHS exemption that auto electronics has for lead, it would not surprise me.

Read more: http://blogs.indium.com/blog/an-interview-with-the-professor/0/0/lack-of-care-in-reporting-can-mislead-greatly-re-tin-whiskers#ixzz0j65EllRe

Bob Landman Virtual PCB

Virtual PCB Chat March 2010

ET Products (03/03/2010 19:21:26):I've been to several recent DFR seminars and training where industry reliability experts make it clear they're still seeing whiskers as one of the top causes of failures. The consensus among those I've had contacat with is go leaded for critical products or those that need a long lifespan.

Bob Landman (03/03/2010 19:34:10):they will not emerge from soldered areas, that is true

Bob Landman (03/03/2010 19:44:37):You can't accelerate the testing with any degree of confidence. The best studies take a long time. the industry has a 6 month test - not long enough

Keith Armstrong article

The US Government’s National Highway Traffic Safety Agency (NHTSA) has been wanting to speak to me for some weeks, to discuss the EMI implications of Toyota’s spate of sudden unintended acceleration incidents. They said they wanted to speak to me because they had no-one on their staff with my experience or knowledge of EMI and EMC.

I imagine the fact that I’ve been presenting IEEE EMC Symposium papers on EMC and Functional Safety since 2001, including one addressed to the auto industry at a symposium in Detroit in 2008, played a part in their decision.

They also said they wanted to speak to my colleague, Dr Antony Anderson (www.antony-anderson.com), a forensic electrical engineer, because they had no-one with his knowledge or experience either.

I eventually spoke for over an hour with two of their senior officers, on February 2nd, while I was in Florida attending a Sudden Unintended Acceleration case as an Expert Witness against the Ford Motor Company (my first ever appearance in court, anywhere, for any reason!).

Unfortunately, a confidentiality agreement prevents me from describing what we discussed.

Armstrong paper

Lead-free soldering

Its really just another cause of intermittent or fixed short-or-open circuits in electronic PCBs and modules - but one that would not have been any problem until a few years ago, and so could have caught Toyota by surprise.

John R Barnes has created a monumentally huge library of references to the problems of lead-free soldering, especially tin whiskering, see www.dbicorporation.com/rohsbib.htm. Prepare to be totally overwhelmed!

Removing lead from solder has the following effects:

9.1 Tin whiskers

These will grow out of soldered joints and can contact other conductors, causing short-circuits between PCB copper traces and the pins of connectors. They are often no longer than 0.5mm (about 1/50th of an inch) but can grow to 1mm (about 1/24th of an inch) or longer, especially in damp conditions.

Even at 1/50th of an inch they can short between the pins on a modern integrated circuit (IC). And the process of removing the PCB for inspection can brush them off, so you never find them.

And if you didn't accidentally brush them off, they are so thin they are very hard to see - you need a powerful microscope. They are as fine as the finest spider-web threads, yet can carry sufficient current to short-out the electronics. You won’t see them unless you are looking for them.

Being so thin, they can wave around in the breeze and/or due to shocks, vibration and acceleration, causing intermittent short-circuits.

The iNEMI organisation has published guidelines (www.inemi.org) on how to ensure that tin whiskers don’t grow too long, but I don’t know to what extent these are followed by suppliers of electronics to the car industry in general, or Toyota in particular.

9.2 Brittle solder joints

Solder joints made using lead-free solder are less resilient, more brittle, more prone to cracking, especially in areas with large temperature excursions and vibration (e.g. motor vehicles), and especially under large devices such as BGAs – resulting in more open-circuits on PCBs.

These cracks may be invisible without X-Ray inspection, and will often be intermittent.

E.g. when the PCB is mounted in its box and mounted on the vehicle, it is bent slightly and that opens the connection or makes it subject to vibration. But when the PCB is taken out for inspection, it tests just fine.

9.3 Tin Pest

Lead-free tin tends to revert to a different crystalline structure, which means it becomes just grey dust and falls off or is blown away by a breeze. Obviously creates an open-circuit solder joint, and one that is easily spotted if it occurs.

9.4 Higher soldering temperatures can weaken components

Lead-free soldering has to use higher temperatures, and this increases the stresses on the components that are mounted on the board during the soldering process.

Another issue is that the range of temperatures for lead-free soldering is not only higher than for traditional solder, but it is also narrower. Some PCB-assemblers’ soldering equipment may not be able to maintain the temperature within the required bands at all times, causing an increased number of bad joints and/or heat-damaged components.

So the actual components (especially ICs) may test OK when newly-assembled, but fail or behave incorrectly when in use, due to internal changes that require an electron microscope to see.

Electronic tin whiskers may be behind Toyota recalls

TechEye: "An expert on electromagnetic interference was approached by the US government for an independent assessment of problems that have caused the massive recall of Toyota cars.

According to a document seen by TechEye, and written by EMI expert Keith Armstrong, the idea that the Toyota recall is due to sticking pedals is a smokescreen. In the document, Armstrong said he was contacted by the US government's National Highway Traffic Safety agency to discuss the EMI (electro magnetic interference) implications behind cases of unintended acceleration.

He says tests performed by the motor industry, by the Japanese government and the US government show it's almost impossible to stop a runaway behicle with the brakes. And if EMI is involved in cases like these, there's no trace of a defect after an incident."

He said that lead free soldering is also a problem and can cause tin whiskers to gow which cause short circuits. This problem is documented here, and has caused serious problems in the computer industry previously.

Are Solder-Related Tin Whiskers Implicated in Toyota Sudden Acceleration Issues?

INDIUM CORPORATION: "After my recent post on the fact that there was no data linking tin whiskers to the Toyota sudden acceleration issues, there continue to be more posts saying things like “Tin Whiskers Implicated in Unintended Acceleration Problems."

Many of these posts link back to the earlier TechEye post. The basis for all of the posts, is a paper written by EurIng Keith Armstrong"

Armstrong’s paper is titled: “Toyota ‘sticking pedals’ recall is a smokescreen, Their sudden unintended acceleration problem is caused by electronics either due to EMI, lead-free soldering or software ‘bugs.’” It does not appear that Armstrong’s paper was sponsored or refereed.

Since it appears that this entire wave of reporting implicating tin whiskers, in this important issue, emanates from Armstrong's paper, it is helpful to quote his entire comments on Tin Whiskers:

Read more: http://blogs.indium.com/blog/indium-corporation/0/0/are-solder-related-tin-whiskers-implicated-in-toyota-sudden-acceleration-issues#ixzz0j5ywpk3d

Note that, in this paper, there is no data or any evidence re: tin whiskers discussed from investigating any of the vehicles in question. All of this paper is an opinion. In addition, the title of Armstrong’s paper leaves no room for any other cause, it has to be electronics or software. This position is very strong indeed for having no supporting data.

More recently Bob Landman added these comments to the tin whisker discussion:

“the increased use of electronics in automobiles when mixed with RoHS can make for a deadly cocktail. We don’t know what the causative agent [in regard to the Toyota recalls] was, but I have heard recently of new autos showing up at dealers that will not start. That cause has been linked to tin whiskers.”

Bob heard this. There is no report and no data. Until Bob gives us a reference for some analysis and data, his comments are little more than hearsay. I searched the web in vain to find information related to Bob’s quote. In addition this comment is a little surprising, tin whiskers are usually associated with a certain amount of aging, hence not usually found in new products.

That tin whiskers exist and cause failures is irrefutable. NASA has an excellent website related to tin whiskers and failures caused by them. However, the total number of tin whisker fails reported is less than 100. Many other types of electronic failure modes would appear to be much more common.

My purpose of writing this post is not to suggest that tin whiskers are not a concern in lead-free electronics. However, it is a fundamental principle in engineering and science to only make pronouncements on how something failed, when they can be supported with data. No data supports implicating tin whiskers in the Toyota incidents. It is also troubling how readily many people referenced the work of Armstrong without apparently reading what he said and checking his sources and lack of data.

Read more: http://blogs.indium.com/blog/indium-corporation/0/0/are-solder-related-tin-whiskers-implicated-in-toyota-sudden-acceleration-issues#ixzz0j61dIWfd

Ron Lasky, Indium Corporation

John Barnes

Bibliography: "People can be killed or injured, and their homes and offices/ businesses burned down, when lead-free/ RoHS-compliant electronics self destruct by the new failure modes listed above. There is a lot of discussion right now about whether the sudden unexpected acceleration (SUA) problems with 8 models of Toyota vehicles-- which has forced the recall of over 6 million vehicles in the US-- and 8.5 million vehicles worldwide-- is due to tin whiskers."