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All modern cars are packed with a wide array of safety features, some of which are more well-known than others. Airbags are among the most well-known features, having been mandatory in all new passenger vehicles in the United States since 1998. The number of airbags fitted to a car and their exact configuration differ between makes and models, although the vast majority of new cars have six or more.
Deploying every single one of those airbags in a crash can increase the cost of repairing a car, and in some situations, it might even be dangerous. Children can be injured by the force of an airbag deploying if they’re sitting in the front passenger seat, which is why current guidelines suggest that children under 12 years old should only ride in a car’s rear seats with proper restraints.
To help reduce the risk of an airbag causing injury to a young person in the passenger seat, carmakers fit the seat with a weight sensor. If the weight sensor in your car reports a reading consistent with the weight of a child and a second sensor within the seatbelt detects that the belt has been fastened, the airbags will be automatically switched off. An indicator light will then appear to let you know that the passenger airbags are temporarily inactive. If the weight sensor detects a person sitting in the seat when the seatbelt isn’t fastened, you’ll be met with a seatbelt chime as a reminder to belt up.
What happens when passenger seat sensors stop working?
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The combination of the passenger seat weight sensor and the seatbelt sensor can help your car detect when someone’s in the car with you, but the system isn’t foolproof. Both sensors can be tricked, and that can impact how your car’s safety systems work. Seatbelt sensors can be tricked using dummy seatbelt buckles, although given the clear safety risk of not wearing a seatbelt, it’s best never to use those kinds of car accessories.
Likewise, weight sensors can also be fooled. Leaving heavy luggage on the passenger seat can result in the car’s safety systems assuming that there’s a child sitting there, and can trigger a seatbelt chime as a result. Where possible, it’s best not to leave luggage on the front seats at all.
There have also been some cases where the sensors can give incorrect readings because they’ve been installed incorrectly or have broken over time. In 2024, Honda announced that it was recalling over 750,000 vehicles in the U.S. due to the risk of passenger seat weight sensors starting to crack, which stopped the airbag suppression system from working properly. Another recall was issued by the Japanese automaker in 2026 for the same issue, with a further 98,000 vehicles involved.
It isn’t just Honda either. Per the NHTSA, Ford also issued a recall for certain examples of the Maverick and Bronco Sport, again because the passenger seat sensors could fail. It’s just one of a litany of recalls issued by the Blue Oval in 2026, including 19 different recalls in just the first three months of the year.