Key facts
- The NHTSA has upgraded its investigation into brake problems in General Motors vehicles to an "engineering analysis."
- The probe covers electric vehicles, including those built in partnership with Honda, and some non-EV models.
- Hundreds of incidents, including over 20 crashes or fires and at least six injuries, have been reported.
- The issue is linked to GM's "eBoost" brake-by-wire system, specifically potential fractures in the spindle.
- NHTSA is concerned about "immediate loss of brake assist" that could lead to extended braking distances.
- Over 1 million vehicles may be affected by the brake problems.
The National Highway Traffic Safety Administration (NHTSA) has escalated its investigation into brake problems affecting General Motors vehicles, including electric models and some gasoline-powered ones. The probe, now an "engineering analysis," is the highest level of scrutiny NHTSA's Office of Defects Investigation (ODI) performs and often precedes a recall.
The investigation stems from hundreds of reported incidents, including over 20 crashes or fires and at least six injuries. Initial complaints, typically involving a "Brake System Failure" message, began two years ago with 2023 Cadillac Lyriq models. GM had identified the issue as fractures in the spindle of its "eBoost" brake-by-wire system.
However, ODI stated it continued to receive reports of braking assistance loss that were inconsistent with GM's explanation. These reports described an "immediate loss of brake assist" during braking, which the regulator warned could lead to extended stopping distances and increase the risk of a crash.
The eBoost system, which uses an electronic rather than mechanical link between the pedal and the braking system, has been gradually rolled out since 2019. It is present in popular GM EVs like the Blazer EV, Equinox EV, and Cadillac Lyriq, as well as Honda Prologue and Acura ZDX models developed in a joint venture. The system was also used in GM's abandoned Cruise Origin autonomous vehicle.
Incidents reported to NHTSA include a 2025 Lyriq driver losing brakes while parking, resulting in a crash through a store front, and a 2024 Blazer EV driver deliberately steering into a curb to avoid a collision.