US regulator escalates probe into brake failures in GM electric vehicles
NHTSA has upgraded its investigation into brake problems in General Motors EVs to the highest level after hundreds of complaints, more than 20 crashes or fires, and at least six injuries. Over a million vehicles could be affected.
The U.S. National Highway Traffic Safety Administration (NHTSA) has escalated its investigation into brake problems affecting General Motors electric vehicles, including models built jointly with Honda. On Monday, the agency's Office of Defects Investigation (ODI) said it was moving the probe to an "engineering analysis," the highest level of investigation ODI conducts and often a precursor to a recall order.
The investigation began in April 2024 after owners of 2023 model year Cadillac Lyriq vehicles reported a "Brake System Failure" warning appearing at startup or after coming to a stop. GM's own internal investigations at the time linked the issue to fractures in the spindle of its "eBoost" brake-by-wire system.
However, ODI said it has continued receiving reports of lost brake assistance that don't match GM's spindle-failure explanation. These additional complaints describe an immediate loss of brake assist while drivers were actively braking, which the agency says could extend stopping distances and raise the risk of crashes or injuries.
Over a million vehicles potentially affected
The brake issue extends beyond EVs to some conventional models, including the Chevy Colorado, GMC Canyon, and the Buick Enclave and Envision, with more than 1 million vehicles potentially affected. The eBoost system, introduced in 2019, replaces the mechanical link between the brake pedal and braking system with an electronic connection, allowing GM to adjust brake feel across driving modes. It is used in popular GM EVs such as the Blazer EV, Equinox EV, and Cadillac Lyriq, as well as the Honda Prologue and Acura ZDX built through GM's joint venture with Honda.
Among the incidents cited, the driver of a 2025 Lyriq reported losing braking power while parking, causing the vehicle to crash into a storefront. In another case, the driver of a 2024 Blazer EV said they had to deliberately steer into a concrete curb to avoid a collision at an intersection.
