The National Highway Traffic Safety Administration (NHTSA) has escalated its investigation into brake failures in General Motors electric vehicles to an engineering analysis, the agency’s highest level of scrutiny before a potential recall. The probe, announced Monday, now covers more than 1 million vehicles and follows hundreds of complaints, over 20 crashes or fires, and at least six injuries.
The investigation began in April 2024 after owners of 2023 Cadillac Lyriq vehicles reported receiving a “Brake System Failure” message on startup or after stopping. GM attributed the issue to fractures in the spindle of its “eBoost” brake-by-wire system, but NHTSA’s Office of Defects Investigation (ODI) says it has received additional reports of an “immediate loss of brake assist” during braking that are “inconsistent with GM’s description of a spindle failure.”
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Scope of the probe: More than just EVs
The eBoost system, introduced in 2019, eliminates the traditional mechanical link between the brake pedal and the braking system, using an electronic connection instead. This allows GM to adjust brake feel across different driving modes. The system is installed on several of GM’s most popular EVs, including the Blazer EV, Equinox EV, Cadillac Lyriq, and the Honda Prologue and Acura ZDX, both produced through GM’s joint venture with Honda. The abandoned Cruise Origin autonomous vehicle also used eBoost.
However, the brake problems extend beyond electric models. The probe also covers the Chevy Colorado, GMC Canyon, and Buick Enclave and Envision, all of which use the eBoost system. In total, ODI says more than 1 million vehicles may be affected.
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In one incident reported to NHTSA, the driver of a 2025 Lyriq lost brakes while pulling into a parking space and crashed through a storefront, coming to rest “mid-way in the store.” In another, a 2024 Blazer EV driver said they had to deliberately steer into a concrete curb to avoid a “catastrophic intersection collision.”
What the engineering analysis means for GM owners
An engineering analysis is the final step ODI typically takes before requesting a recall. The agency said it needs to further analyze the potential for failures in the eBoost system, particularly the reports of sudden loss of brake assist that could extend braking distance and increase crash risk.
For owners of affected vehicles, this escalation is a signal that NHTSA is taking the issue seriously. If the agency determines a safety defect exists, GM could be required to notify owners and offer free repairs. GM has not issued a recall related to this issue as of this writing, and the company has not publicly commented on the upgraded probe.
The investigation also raises broader questions about the reliability of brake-by-wire systems, which are becoming more common as automakers shift to electric platforms. Unlike traditional hydraulic systems, these electronic systems rely on sensors and actuators, and failures can be more difficult to diagnose.
NHTSA’s move comes amid heightened scrutiny of EV safety and software-related issues across the industry. For GM, which has bet heavily on its Ultium EV platform, a potential recall would be a setback as it works to scale production and convince consumers of its electric vehicles’ reliability.
Owners of affected vehicles who experience brake issues can file a complaint with NHTSA’s website. The agency’s investigation remains open, and further updates are expected as the engineering analysis progresses.
This article is for informational purposes only and does not constitute financial or investment advice. Vehicle safety issues and regulatory actions can be volatile and uncertain; readers should monitor official NHTSA announcements for the latest developments.
