NHTSA increases scrutiny on GM EV brake problems after hundreds of incidents

Increased Federal Scrutiny on GM Brakes

The National Highway Traffic Safety Administration (NHTSA) has escalated its investigation into brake problems in General Motors (GM) vehicles, including electric vehicles (EVs) and some non-EV models. This upgrade to an "engineering analysis" is the highest level of investigation performed by NHTSA's Office of Defects Investigation (ODI) and often precedes a recall recommendation. The probe follows hundreds of reported incidents, over 20 crashes or fires, and at least six injuries.

Affected Vehicles and Reported Issues

The brake issues affect more than one million vehicles, including popular GM EVs like the Cadillac Lyriq, Blazer EV, Equinox EV, and models built in partnership with Honda such as the Honda Prologue and Acura ZDX. Non-EV models like the Chevy Colorado, GMC Canyon, Buick Enclave, and Envision are also implicated. Initial complaints described a "Brake System Failure" message upon vehicle startup or after stopping, while later reports detailed an "immediate loss of brake assist" during braking, potentially increasing stopping distances and crash risk.

The eBoost System Under Investigation

GM's eBoost brake-by-wire system, introduced in 2019, is at the center of the investigation. This system replaces the traditional mechanical link between the brake pedal and the braking system with an electronic one. GM had previously attributed the problem to fractures in the spindle of the eBoost system, but ODI's continued receipt of reports inconsistent with this explanation has prompted a deeper analysis into potential failures within the eBoost system itself.