Federal Regulators Expand GM Brake Failure Probe to More Than 1 Million Vehicles

Federal auto safety regulators are expanding an investigation into electronic brakes used in some of General Motors’ most popular models.The National Highway Traffic Safety Administration (NHTSA) on Aug. 21 opened an engineering analysis to assess potential safety risks associated with malfunctions of GM’s eBoost braking system.The investigation covers all GM vehicles equipped with the technology, including two models developed in partnership with Honda.NHTSA opened its preliminary investigation in 2024. It initially focused on complaints of lost eBoost brake assist in 2023 model-year Cadillac Lyriq electric SUVs, covering some 3,300 vehicles.Introduced in 2019, the eBoost system uses an electric motor to provide brake assist, making the brake pedal easier to push.GM has installed eBoost on several of its major EVs, including the Chevrolet Blazer EV, Equinox EV, and the Cadillac Lyriq.The Cruise Origin, a now-discontinued autonomous vehicle that had no steering wheel or pedals, also used the system.The expanded NHTSA review now includes all those EVs as well as several gasoline-powered models equipped with eBoost, including the Chevrolet Colorado, GMC Canyon, and Buick Enclave and Envision.Two electric crossovers developed in a GM-Honda joint venture—the 2024–2026 Honda Prologue and Acura ZDX—are also included in the review.NHTSA estimates that the expanded investigation covers more than 1.16 million vehicles, a dramatic increase from the roughly 3,300 vehicles included in the original probe.The heightened scrutiny comes after regulators received reports involving 221 incidents, including 21 crashes or fires and at least six injuries.During the preliminary investigation, GM provided records from several internal reviews examining loss of brake assist allegedly linked to fractures of a spindle inside the eBoost unit.According to GM, a spindle fracture does not immediately disable all braking-related functions. Anti-lock brakes (ABS), stability control, and traction control continue operating until the vehicle comes to a stop.Once halted, the vehicle loses brake assist as well as ABS, stability control, and traction control.However, federal investigators said they were receiving reports that do not appear to fit GM’s description of a spindle fracture.Those reports allege an immediate loss of brake assist during braking, rather than a failure occurring only after the vehicle has come to a stop.“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,” a GM spokesperson said in a statement to The Epoch Times.“We will continue to cooperate with NHTSA as its investigation proceeds.”Neither GM nor NHTSA has announced a recall related to the investigation.An engineering analysis is the final investigative step before the agency can formally demand that a manufacturer issue a recall.