Tin whiskers may have caused Toyota recalls

An expert on electromagnetic interference has been approached by the US government to give an independent assessment of the problems that have been the cause of a massive recall of Toyota cars.

OEMTechEye claims that they have seen a document written by EMI (electro magnetic interference) expert Keith Armstrong, saying that the Toyota recall due to sticking pedals is only a smokescreen. In the document, Armstrong said he was contacted by the US government's National Highway Traffic Safety agency to discuss the EMI implications that could have caused unintended acceleration.

Armstrong said that tests performed by the motor industry, by the US government and the Japanese government show it's almost impossible to stop a runaway vehicle with the brakes. If EMI is involved in an incident, it will not leave any traces. He said that if electronic circuits, software or firmware in cars go full throttle or is exposed to another error, there could not be more stress seen than if it was behaving normally. The cause of the fault is then undetectable afterwards.

Armstrong said that manufacturers are denying that EMI could have caused the sudden acceleration, but that view is logically unsound. He said that this is a "bankrupt argument" and that any competent design engineer knows this. Complex electronic systems are hard to make reliable enough for safety. He also claimed that electronics systems in automobiles do not use the same safety principles that are common in other industries. The standard for functional safety is IEC 61508[2], but the auto industry is lagging behind and has only just produced the first draft of its own version of the standard.

Armstrong said that lead free soldering also can be a problem and can cause tin whiskers to grow, which can cause short circuits. This problem has earlier caused serious problems in the computer industry. He concludes that software also can be affected by EMI and can cause instability to electronic circuits, according to Techeye.