BMW is recalling more than 390,000 vehicles equipped with air bag inflators that could explode and send metal fragments flying at passengers, possibly causing injury or death.
The recall affects certain 2006-2011 3 Series Sedan (324i, 325i, 325xi, 328i, 328xi, 330i, 330xi, 335i, 335xi), 2006-2012 3 Series Sportswagon (325xi, 328i, 328xi), and 2009-2011 3 Series Sedan (335d) vehicles, according to a recall notice posted by the National Highway Traffic Safety Administration.
The automaker says the original steering wheel may have been replaced with a sport or M-sport steering wheel equipped with a defective Takata air bag module that can explode during deployment.
"The Takata PSDI-5 inflator propellant may experience an alteration over time, which could potentially lead to overly aggressive combustion in the event of air bag deployment. Depending on the circumstances, this potential could create excessive internal pressure when the air bag is deployed, which could result in the body of the inflator rupturing upon deployment," the notice said. "In the event of an inflator rupture, metal fragments could pass through the air bag cushion material, which may result in injury or death to vehicle occupants."
BMW said the potential for such ruptures may occur after several years of exposure to persistent conditions of high absolute humidity and high temperatures.
According to the recall notice, the steering wheels were installed by an owner, even though they were not officially offered or approved by BMW as replacement parts. The originally equipped air bag module did not contain an inflator with ammonium nitrate.
"US market customers could have changed their vehicle's original production configuration steering wheel, via an unapproved replacement process, to a sport or Msport steering wheel, with the unintended consequence of replacing an ammonium nitrate-free air bag inflator with a PSDI-5 inflator," BMW said.
Dealers will inspect and replace the driver's air bag module as necessary, free of charge. Owner notification letters are expected to be mailed by late August.
BMW has not received any reports of any accidents or injuries that may be related to this issue.