At speeds between 10-15 mph, the Mazda CX-90’s smart brake system could falsely detect objects and unexpectedly brake.
This week, Mazda launched a new recall covering 9,914 examples of its flagship CX-90 SUV for an inadvertent braking problem with its driver assistance system. According to what the automaker told the National Highway Traffic Safety Administration (NHTSA): “The brakes may activate suddenly due to false detection of certain objects at low speed (10-15MPH) driving.”
Mazda says the problem is the vehicle’s inability to tell a vehicle’s reflection apart from an approaching object like a diagonal metal wall or an object on the side of the road. This is due to improper programming of the vehicle control module, or VCM. Naturally, the CX-90 unintentionally braking — which we commonly refer to as ‘phantom braking’ — may increase the risk of a rear-end accident.
The company has been investigating the issue since January 19, 2023, where it “received field information from outside of the United States and Territory markets,” since the CX-90 had not yet gone on sale in North America at that time. By May 10, 2024, Mazda says it has not received field reports in the North American market, nor has it gotten any reports of accidents or injuries. Nevertheless, it determined nearly 10,000 vehicles may be at risk for inadvertent braking from the smart brake system (SBS), and launched a voluntary recall to address the problem anyway.
How do I know if my CX-90 is affected?
On NHTSA documents, the percentage of vehicles estimated to have the defect is 1%. However, while that may reflect a significantly low chance of a CX-90 having this issue, manufacturers can also enter 1% as “unknown”, meaning it’s unclear exactly how many vehicles have the problem. As a result, Mazda is CX-90s built between December 27, 2022 and September 12, 2023, ranging (in non-sequential order) from JM3KKEHD6R1100044 to JM3KKEHD8R1131022.
Fortunately, the fix is fairly straightforward. Owners can take their CX-90 to their local Mazda dealer, and a technician will update the VCM software with “improved logic” to prevent false detection and, by extension, random and unexpected braking events.
Dealers have already been alerted to the problem as of May 21, and Mazda will mail out recall notices to owners on July 17. So far, this is the sixth recall of the Mazda CX-90 since its launch, with other issues ranging from inaccurate pedestrian warning sounds when the vehicle is reversing to unexpected engine shutdowns and loss of power steering assist.
While some reports list the “Hybrid” Mazda CX-90 as the affected model, it’s important to note this recall campaign does affect both the 3.3-liter straight-six (mild hybrid) and 2.5-liter plug-in hybrid (PHEV) versions. Mazda’s recall number is 6724E, while the NHTSA’s number for this recall is 24V-349.
