NHTSA Upgrades GM eBoost Brake Investigation to Engineering Analysis, 1.16 Million Vehicles Affected

The US National Highway Traffic Safety Administration (NHTSA) announced on August 24, 2026, that it has upgraded its investigation into General Motors' eBoost brake-by-wire system to an engineering analysis (EA26006), expanding the scope to 1,164,820 vehicles. Engineering analysis is the highest investigation stage before a potential recall, and this upgrade follows a further review of the failure modes.

The issue first emerged in April 2024, when some owners of the 2023 Cadillac Lyriq complained that the brake pedal suddenly became hard, with a "brake system failure" warning appearing during vehicle startup or driving. NHTSA's investigation found that the failure modes reported by owners did not match GM's description; most complaints indicated a sudden loss of brake assist while driving, rather than failure only after the vehicle had come to a stop.

To date, the problem has accumulated 745 failure reports, linked to 22 crashes or fires, of which 5 resulted in injuries. No fatalities have been reported. The investigation covers the 2023 to 2026 model years of the Cadillac Lyriq, Optiq, and Celestiq; Chevrolet Colorado, Blazer EV, Equinox EV, and Traverse; GMC Canyon and Acadia; Buick Enclave and Envision; as well as the autonomous vehicle unit's Cruise Origin. The Honda Prologue and Acura ZDX, which GM builds for Honda, also use the same system and are included in the investigation.

The eBoost brake-by-wire system has been in use since 2019, with no mechanical hard connection between the pedal and the braking mechanism, relying entirely on electronic signals. NHTSA will next assess the structural issue of spindle failure and the effectiveness of GM's existing remedial measures.