NHTSA probe of rupturing ARC airbag inflators echoes Takata

“In Takata, every one of those airbags not only had the condition, but they were getting worse over time,” said Michael Brooks, executive director of the Center for Auto Safety. “I don’t think that is what is occurring in the ARC airbag situation. It seems like there’s not this environmental component that’s going to make these airbags more dangerous over time, so NHTSA is going to have a tougher argument to make for a recall.”

Since the launch of the ARC investigation in 2015, automakers — including BMW, Ford and Volkswagen — have initiated eight recalls to address potential safety defects with ARC airbag inflators.

Most recently, General Motors called back nearly 1 million 2014-17 Buick Enclave, Chevrolet Traverse and GMC Acadia vehicles equipped with the airbag inflators.

GM, which has been working with a third-party engineering firm to assist with its own investigation, told NHTSA that “the reason for these inflator ruptures remains unknown.”

Several automakers — including Ford, Hyundai, Kia, Stellantis and VW — told Automotive News they are continuing to monitor or investigate the situation and are cooperating with NHTSA.

To be sure, NHTSA is not required to discover a root cause or have an engineering explanation for a defect in order to seek a recall, according to Friedman. “NHTSA simply needs to determine that there is an unreasonable risk to safety.”

In the agency’s letter to ARC, Ridella pointed to a welding process used by the company that could produce a byproduct known as “weld slag.”

“Should any debris of sufficient size be in the inflator center support, the exit orifice could become blocked,” Ridella said. “Blockage of the exit orifice could cause over pressurization of the airbag inflator” and consequently result in rupture.

ARC, which in January 2018 installed instruments to detect excessive weld slag and other debris, said it believes the ruptures resulted from “one-off manufacturing anomalies” that were addressed by automakers in subsequent recalls.

“Moreover, while weld slag has not been confirmed as the root cause in any of the seven incidents [in the U.S.], weld slag was found not to be the root cause in two of these seven ruptures,” the company told NHTSA.

The inflators have been used in vehicles made by at least 12 automakers. NHTSA has not yet released a complete list of all makes and models that might have the inflators, nor has it provided a figure for how many vehicles might be affected.

The likely next step, according to Brooks, is NHTSA will file its initial defect determination and then hold a public hearing.

“That said,” noted Friedman, “if the supplier continues to fight, it’s still the car company’s responsibility to take care of their customers — period. They don’t get to point fingers.”