Put Brakes on EMI ‘Conclusions’

I know and respect the team at Circuitnet, but it seems like they made a pretty serious goof the other today.  Their top story  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 Nov. 12, 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

P.S.: 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.

In summary: Double yikes!!

Toyota Recall Has Pb-Free Critics in Overdrive

Are Toyota’s gas pedal failures caused by a breakdown in the electronics system? And if so, are the much-publicized recalls tied to a lead-free problem?

That’s been the hot topic on the TechNet email forum for over a week now. The mainstream media, of course, has gotten hold of the issue too, and is running with it like a Camry with a stuck gas pedal.

Here’s a list of some articles to date:

  • MSNBC is considering the likelihood of an issue with the electronics sensors.
  • The Los Angeles Times notes that the electronic throttle system uses sensors, microprocessors and electric motors, rather than a traditional link such as a steel cable.
  • AOL Autos and Autoblog look at a recalled pedal and discuss how possible sources of the problems.

Bob Landman, a reliability expert and a Life Senior Member of IEEE, has been vocal that the connection between lead-free solder and tin whiskers is both real and potentially deadly.  He asserts “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 regards to the Toyota recalls] was, but I have heard recently of brand new autos showing up at dealers that will not start.  That cause has been linked to tin whiskers.”

We do not yet have enough information to determine whether tin whiskers or even lead-free solders are to blame. One would hope Toyota would come clean about the true cause, if indeed it can be determined, so that the industry at large can learn from their mistakes.

UPDATE: Toyota today stated the cause was not electronic in nature.