Engineering Analysis EA15-001: Air Bag Inflator Rupture

The Office of Defects Investigation (ODI) opened PE14-016 in June 2014 based on six inflator rupture incidents involving consumer owned vehicles produced by five vehicle manufacturers.

All six vehicles were operated in Florida or Puerto Rico at the time of the rupture and for the majority of their service life, and were equipped with inflators produced by Takata, a tier-one supplier of automotive air bag systems.

During the course of PE14-016, ODI determined that five additional vehicle manufacturers used inflators of a similar design and vintage also supplied by Takata. No evidence of field failures was found in vehicles produced by these five additional manufacturers.

Nonetheless, at ODI's insistence, all 10 vehicle manufacturers initiated a regional recall within approximately two weeks of the opening of the investigation.

The regions recalled initially included Florida, Puerto Rico, Hawaii, and the U.S. Virgin Islands, areas with high absolute humidity and climatic conditions believed to be a significant factor in the inflator ruptures.

As part of the recall actions, inflators removed from remedied vehicles are to be returned to Takata for testing.

Takata's initial test results on passenger inflators from remedied vehicles indicated a much higher than anticipated rupture frequency for inflators returned from Florida.

Accordingly ODI requested all 10 manufacturers expand the regional recalls for passenger inflators to include other geographic areas where high absolute humidity conditions exist, including the Gulf States and other coastal areas.

Takata's testing of the passenger inflators to date continues to indicate this geographic area as having the highest risk, with no ruptures occurring from inflators returned from outside the expanded recall regions.

During PE14-016 four additional passenger inflator field events occurred, all in vehicles from the same expanded geographic region.

Also during PE14-016 four additional driver inflator field events occurred including two in vehicles from regions not known for high absolute humidity, specifically California and North Carolina.

Accordingly, ODI requested all five of the affected vehicle manufacturers currently using the subject Takata driver inflators expand to nationwide recalls.

Significantly, neither of the affected vehicle manufacturers or Takata provided any explanation to account for these two driver air bag inflator ruptures outside the area of high absolute humidity.

Takata testing of returned driver inflators indicates a lower rupture frequency as compared to passenger inflator testing.

All test ruptures reported by Takata to date have occurred on inflators returned from high absolute humidity areas.

The investigation now includes all manufacturers and vehicles known to be affected at this time.

ODI's investigation will focus on, among other things, root cause analysis, other potential defect consequences, identification of affected vehicles scope, and adequacy of the remedy.

The five ODI reports cited above can be reviewed online at http://www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers: 10537899, 10568848, 10585224, 10605877, 10651492