— Nissan LEAF "passenger airbag off" warnings caused federal safety regulators to open an investigation in 2019, but the investigation is now closed after the government didn't find enough evidence to indicate additional action is necessary.
The National Highway Traffic Safety Administration (NHTSA) received a petition to investigate airbag occupancy sensor failures in LEAF cars.
The petition led to a formal investigation into 2011-2012 cars with occupant classification system (OCS) sensors that failed and deactivated the passenger airbags.
Nissan didn't include 2011-2012 LEAFs in a 2016 recall of 2013-2016 LEAFs because Nissan said the passenger airbag occupant classification systems were different.
Customers reported warning lights that said the passenger airbags were off even when adults were in the seats.
Nissan sent information to NHTSA describing how 76 LEAF cars suffered passenger occupancy sensor failures, a rate of about 0.4% on cars in service for eight to nine years.
Safety regulators determined when the passenger seat sensor fails, a driver receives two different warning indicators on the instrument panel.
NHTSA says the warnings "provide clear and unambiguous notice to occupants that an OCS problem has been detected, and the owner's manual provides further information regarding the meaning and consequences of the detected failure, as well as advice to seek service."
A diagnostic trouble code will also be stored and the warnings remain active until the problem has been repaired.
Nissan believes there is no unreasonable risk to safety, and collected parts show "external factors (e.g., damage from foreign objects) were responsible for the failures, rather than a design or manufacturing defect."
NHTSA says it agrees with Nissan that a recall of 2011-2012 isn't needed because of the multiple warnings about sensor failures, and due to the low incidence rate in cars considered "older."
The automaker also says most of the complaints about passenger airbag failures concerns the high cost to repair the occupant classification systems.
Nissan says it is considering lowering the repair cost to help with customer complaints about the expense.
The government says it will get involved again if the circumstances change.