Shimizu: Takata Hasn't Found The Cause Of Airbag Failures

Cameron Aubernon
by Cameron Aubernon
shimizu takata hasn t found the cause of airbag failures

Takata has yet to find the root cause of the defect affecting its airbags; Autoliv will supply replacements to Honda; and Toyota, Mazda and Chrysler are expanding their recalls.

Reuters reports Takata hasn’t found the cause behind the catastrophic failures in its airbags, per testimony given by safety executive Hiroshi Shimizu before Congress Wednesday. That said, Shimizu said his company was of “the strong opinion that (there) is a factor contributing to this defect: which is high humidity, temperature and the life of the product.” He also claimed the ammonium nitrate used in the airbags was safe and stable, though he admitted replacements weren’t coming fast enough.

Meanwhile, competitor Autoliv announced it would supply replacements to Honda for vehicles in the United States. The automaker had mentioned before Congress it was in talks with the supplier and another, Daicel, regarding expanded production to replace modules in a nationwide recall. Autoliv will add capacity in its existing plants, with deliveries to come after six months.

Among the other affected automakers, Chrysler, Toyota and Mazda have stepped up their individual recall efforts. AutoGuide says the subsidiary of Fiat Chrysler Automobiles has called back 149,150 Dodge Ram 1500, 2500 and 3500 models from the 2003 model year, covering Alabama, Florida, Georgia, Hawaii, Louisiana, Mississippi, Texas, and the U.S. territories of American Samoa, Guam, Puerto Rico, Saipan and the Virgin Islands. The National Highway Traffic Safety Administration stated the move wasn’t enough, and is looking at what action to take next.

Over in Japan, Bloomberg reports Toyota is recalling 190,000 affected vehicles in its local market and in China. The recall comes on the news of a catastrophic detonation at a junkyard of a Takata airbag inside a 2003 WiLL Cypha; the detonation was part of the procedures outlined by Japan’s Automobile Recycling Law, which also requires dismantlers to report any problem to the automaker to determine if a recall is necessary.

Finally, The Detroit News says Mazda is recalling 40,000 more vehicles — including the 2003-2007 Mazda6, 2004-2008 RX-8, 2006-2007 Mazdaspeed6, 2004-2005 MPV and 2004 B-Series — in Florida, Hawaii, Mississippi, Louisiana, Georgia, Texas and Alabama. The automaker previously recalled 44,000 units in the U.S. and 2,600 in Puerto Rico.

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  • Norman Yarvin Norman Yarvin on Dec 06, 2014

    Uh, "...the ammonium nitrate used in the airbags..."? Isn't that the problem right there? They used ammonium nitrate, a hygroscopic material. It's "stable" in the sense that it won't decompose under normal circumstances; but it absorbs water from the atmosphere and, above a certain humidity, turns itself into a little puddle. Then as it dries out, it recrystallizes into a different form. Presumably they tried to seal water out of the airbags; but seals often fail over time, or are flawed from the start; and lots of materials (like plastic films) which seem impervious to water actually let it slowly diffuse through. Once moisture has gotten in, this process (absorbing water and turning into a liquid, then drying out and recrystallizing) would repeat itself every day, due to the humidity dropping during the day then rising at night. (With a constant amount of moisture present, humidity falls when the temperature rises.) In the airbags, they must have mixed the ammonium nitrate with something else, as pure ammonium nitrate is not a suitable propellant. And the exact nature of the mixture must have been important. The more finely divided the material, the faster the boom. The changing shape of the ammonium nitrate must have played havoc with whatever they'd done to control the speed of the boom. I don't know how they could ever have thought this would work. If they didn't get problems with exploding too fast, they'd have gotten problems with exploding too slow. (And I wouldn't be surprised if the latter also sometimes turned out to be a problem with these airbags.) But ammonium nitrate is among the cheapest of materials, which is presumably why they tried to make it work.

  • Andrewa Andrewa on Dec 07, 2014

    Well, you know how everything is bigger and better in Texas? The biggest non nuclear bang ever to happen in the US occurred in Texas and the stuff that made the bang? Ammonium nitrate that someone had wet with steam to try and put it out as it was on fire!

    • See 2 previous
    • Petezeiss Petezeiss on Dec 08, 2014

      @andrewa The damage from the Texas City explosion was actually compared in contemporary news accounts to Nagasaki. By people who'd seen Nagasaki. Holy crap...

  • Norman Stansfield This is what you get when you run races to keep the cars bunched together for more excitement. F1 doesn't seem to have this problem after the first few laps.
  • SCE to AUX Too many cars = more wrecks. With today's speeds on essentially the same old track, starting with half the cars could reduce the congestion at the end. Or maybe it would increase the problem because the herd wouldn't thin early on.I say no overtime - finish at 500 miles and no more.
  • Garagezone There was an Indy 500 yesterday? Hmmmm...
  • Mark Morrison Sad it just reminded me how good TTAC once was … required daily reading.