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NHTSA expands GM probe
The U.S. National Highway Traffic Safety Administration (NHTSA) has intensified its investigation into potential brake problems in General Motors vehicles, focusing on GM electric vehicles and models developed in partnership with Honda.
“The total number of vehicles that could be covered by the investigation exceeds 1 million.”
The regulator is reviewing hundreds of complaints about brake system performance, more than 20 reports of crashes or fires, and at least six injury cases, and the total number of vehicles that could be covered exceeds 1 million.
NHTSA’s vehicle defects division began its review in April 2024 following complaints from owners of 2023 Cadillac Lyriq models, and the case has moved to the engineering analysis stage, which may lead to a decision to recall the vehicles.
TechCrunch said the Office of Defects Investigation upgraded the probe to an “engineering analysis,” describing it as the highest level of investigation that ODI performs and often a step before a recall.
The investigation centers on GM’s eBoost brake-by-wire system, which replaces the conventional mechanical connection between the brake pedal and braking mechanism with electronic controls introduced in 2019.
Conflicting reports on braking
GM linked the issue to cracks in the spindle of the eBoost electronic braking system, but NHTSA continued to receive complaints about a sudden loss of brake assist that did not match the scenario described by General Motors.
TechCrunch reported that ODI kept receiving reports of a loss of braking assistance that were “inconsistent with GM’s description of a spindle failure,” and said the additional reports described an “immediate loss of brake assist” while a customer was in the process of braking.
In one crash described to NHTSA, the driver of a 2025 Cadillac Lyriq said they were unable to brake while parking, after which the vehicle drove over a curb and crashed into the front of a store.
Another case involved a 2024 Chevrolet Blazer EV, where the driver said they had to “deliberately steer the vehicle into a concrete curb” to reduce speed and avoid a collision at an intersection.
The Detroit News said the Office of Defects Investigation “has continued to receive reports of loss of brake assist,” and that some reports describe symptoms inconsistent with GM’s description of a spindle failure.
Models under review, next steps
The expanded investigation into GM eBoost braking systems is now looking into another 10 GM models and two Honda Motor Co. models equipped with the same eBoost brake system as the Lyriq, after officials in April opened an investigation into complaints of loss of brake assist in 2023 Cadillac Lyriq.
“Neither GM nor federal safety regulators have called for a recall so far.”
The Detroit News listed GM models under review including Buick Enclave (model years 2024-2026), Buick Envision (model years 2024-2026), Cadillac Optiq (model years 2025-2026), and Chevrolet Blazer EV (model years 2024-2026), along with Chevrolet Colorado (model years 2023-2026) and GMC Canyon (model years 2023-2026).
Neither GM nor federal safety regulators have called for a recall so far, and GM spokesperson Bill Grotz said, “We take these reports seriously and have conducted a thorough investigation, determining the alleged condition does not present an unreasonable risk to motor vehicle safety.”
TechCrunch said the eBoost system was introduced in 2019 and gradually rolled out to more models, including the Blazer EV, Equinox EV, Cadillac Lyriq, and the Honda Prologue and Acura ZDX made with Honda in a joint venture.
The engineering analysis will determine whether the issue is unsafe enough to require a recall, and the TechCrunch account said ODI needs to do further analysis of the potential for failures in the eBoost system.