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Fault with Mazda3’s emergency braking system could cause random activation

The thought that your car might suddenly activate its emergency braking system for no apparent reason is a rather unnerving one.

But that’s the reality facing owners of certain 2019 and 2020 Mazda3 vehicles after the automaker’s U.S. unit recently recalled just over 35,000 of them for repairs.

When working properly, the system automatically activates to prevent a collision with an object that the driver has failed to respond to manually. But a software issue with some Mazda3 vehicles means the system could suddenly kick in even when there’s no threat of a collision ahead.

The company pointed out that no injuries or deaths have so far been reported in connection with the fault.

“The affected vehicles may unexpectedly stop while driving due to inadvertent activation of the Smart Braking System (SBS) automatic emergency braking system,” Mazda explained in a release.

It said that incorrect programming of the SBS software “may cause the vehicle to falsely detect an obstacle in front of the vehicle while driving,” prompting the emergency brake to kick in.

“If the SBS automatic emergency braking system unexpectedly activates while driving, the risk of a rear-end crash from a following vehicle may increase,” the Japanese automaker warned.

Mazda confirmed that it has notified the National Highway Traffic Safety Administration about the fault.

According to Autoblog, the repair will be more straightforward for some cars than others. While affected Mazda3 vehicles with later build dates only require the SBS software to be reprogrammed, those with earlier build dates will have to have the entire instrument cluster replaced or reprogrammed to resolve the issue.

The usual recall procedure involves an automaker contacting affected owners directly, with Mazda aiming to contact everyone involved by February 17, 2020.

Concerned U.S.-based Mazda3 drivers can also get in touch with the company by calling 1-800-222-5500 between 5 a.m. and 6 p.m. PT from Monday through Friday or between 7 a.m. and 3 p.m. PT on Saturday and Sunday. Alternatively, you can email the company.

News that Mazda is having problems with its emergency braking system comes just a couple of months after 800 Nissan Rogue owners complained to the company about their vehicle suddenly slamming on the brakes for no apparent reason. Nissan is currently investigating the issue.

Automatic emergency braking is an increasingly common feature in today’s vehicles, with 20 or so automakers having already committed to making the safety system a standard feature for all new cars by September 2022.

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Trevor Mogg
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