GM EV brake problems draw upgraded federal investigation

General Motors electric vehicles, including ones built in partnership with Honda, are facing increased scrutiny from the National Highway Traffic Safety Administration (the top US auto-safety regulator) after hundreds of incidents, more than 20 crashes or fires, and at least six injuries. The brake problems also extend to some non-EV models, including the Chevy Colorado, GMC Canyon, and the Buick Enclave and Envision — more than 1 million vehicles may be affected in total.

NHTSA’s Office of Defects Investigation opened its probe in April 2024 after owners of 2023 model-year Cadillac Lyriq vehicles reported trouble, and on Monday upgraded it to an “engineering analysis” — the office’s highest investigation level, often a step taken before a company is told to issue a recall. The initial complaints typically described a “Brake System Failure” message appearing at startup or after coming to a complete stop; GM’s internal investigations linked the problem to fractures in the spindle of its “eBoost” brake-by-wire system. But the office said it kept receiving reports of a loss of braking assistance that were “inconsistent with GM’s description of a spindle failure” — an “immediate loss of brake assist” while a driver was actively braking, which it said “could result in extended braking distance, which increases the risk of a crash or injury.”

Introduced in 2019, eBoost replaces the traditional mechanical link between the brake pedal and the braking system with an electronic one, letting GM vary brake “feel” across driving modes; it’s used on the Blazer EV, Equinox EV, Cadillac Lyriq, Honda Prologue, Acura ZDX, and the now-abandoned driverless Cruise Origin. In one crash reported to NHTSA, the driver of a 2025 Lyriq said they lost their brakes while pulling into a parking space and crashed through a storefront; in another, the driver of a 2024 Blazer EV said they had to “deliberately steer the vehicle into a concrete curb” to avoid a “catastrophic intersection collision.” GM said in a statement: “The safety of our customers is the highest priority for the entire GM team. We take these reports seriously and have conducted a thorough investigation, determining the alleged condition does not present an unreasonable risk to motor vehicle safety. We will continue to cooperate with NHTSA as its investigation proceeds.”

Why it matters

An engineering analysis is the step just before NHTSA can push for a recall, so more than a million vehicles across GM’s EV and gas lineups now sit closer to a potential mandatory fix than at any point in this two-year investigation.