Over 1.1M GM vehicles, including EVs, under NHTSA investigation

Key Points:

• The National Highway Traffic Safety Administration (NHTSA) has expanded its investigation into over 1.1 million GM vehicles following reports of brake assist loss, including several electric vehicles and models built for Honda.
• The investigation began in April 2026 after complaints about brake assist failure in 2023 Cadillac Lyriq models, where drivers experienced a "Brake System Failure" message after hard braking.
• GM attributes the issue to spindle fractures in the eBoost system, which cause loss of anti-lock brakes, stability control, and traction control functions once the vehicle stops, though some reports suggest an immediate loss of brake assist.
• The investigation now covers 2023-2026 Cadillac Lyriq, Chevrolet Colorado, GMC Canyon, Buick Enclave, Envision, Chevrolet Blazer EV, Equinox EV, Traverse, Cruise Origin, GMC Acadia, Cadillac Celestiq, Optiq, Acura ZDX, and Honda Prologue models equipped with the eBoost system.
• The Office of Defects Investigation (ODI) has documented 745 incidents related to this issue, including 22 crashes or fires and five injuries, with an estimated 1,164,820 GM vehicles potentially affected.