NHTSA Expands GM Brake Investigation to More Than 1.1 Million Vehicles

September 8, 2026

Federal safety regulators have expanded an investigation into potential brake-assist failures to more than 1.1 million vehicles that use General Motors’ eBoost braking system. The National Highway Traffic Safety Administration opened Engineering Analysis EA26006 on August 21, 2026, after continuing to receive reports involving loss of brake assist. The investigation now covers an estimated 1,164,820 vehicles and expands a federal probe that initially focused on the 2023 Cadillac Lyriq. No recall has been issued, and the investigation doesn’t mean NHTSA has concluded that every vehicle under review contains a defect.

Which Vehicles Are Included in the Investigation?

NHTSA says the following GM vehicles are known to use the eBoost system being examined:

2023–2026 Cadillac Lyriq
2023–2026 Chevrolet Colorado
2023–2026 GMC Canyon
2024–2026 Buick Enclave
2024–2026 Buick Envision
2024–2026 Chevrolet Blazer EV
2024–2026 Chevrolet Equinox EV
2024–2026 Chevrolet Traverse
2024–2026 Cruise Origin
2024–2026 GMC Acadia
2025–2026 Cadillac Celestiq
2025–2026 Cadillac Optiq

The investigation also includes the 2024–2026 Acura ZDX and Honda Prologue as peer vehicles. NHTSA notes that those vehicles were manufactured by GM through its joint venture with Honda and use the system under investigation. Being listed in the investigation doesn’t mean an individual vehicle has been determined to be defective.

The Investigation Started With Cadillac Lyriq Complaints

NHTSA’s Office of Defects Investigation initially opened Preliminary Evaluation PE24011 in April 2024 after receiving complaints about loss of brake assist in 2023 Cadillac Lyriq vehicles. Drivers reported experiencing a hard brake pedal along with a “Brake System Failure” message either at startup or while driving. During the earlier investigation, GM provided regulators with information about internal investigations involving alleged spindle fractures in the eBoost system.

According to GM’s explanation to NHTSA, if the spindle fractures, anti-lock braking, stability control and traction control remain functional until the vehicle comes to a complete stop. After the vehicle stops, however, ABS, brake assist, stability control and traction control can be lost.

Some Driver Reports Describe a More Immediate Problem

NHTSA says it continued receiving reports of lost brake assist after opening the original investigation. Some of those reports don’t appear consistent with GM’s description of how a spindle failure occurs.

Instead of losing brake assist after the vehicle comes to a stop, some drivers have alleged an immediate loss of brake-assist functionality during a braking event. That’s an important distinction from a safety standpoint. NHTSA says sudden loss of brake assist while someone is actively braking could increase stopping distance, potentially increasing the risk of a crash or injury.

Drivers May See Several Brake System Warnings

GM has told regulators that a spindle failure can cause the Electronic Brake Control Module to set one of several diagnostic trouble codes. Those codes can trigger an audible chime and display a “Service Brake System” warning to the driver.

Warning lights for the anti-lock braking system, traction control and brakes may also illuminate. The vehicle’s speed may then be limited to approximately 43 mph. However, because some consumer reports describe symptoms that differ from GM’s expected failure sequence, NHTSA is continuing to investigate exactly how eBoost failures can affect braking.

Hundreds of Incidents Have Been Identified

The expanded investigation follows a substantial number of reports. NHTSA’s opening materials identify 745 incidents after accounting for duplicate reports, drawing from complaints received by the agency and information supplied by GM. The agency’s materials identify crash or fire reports as well as five injury incidents involving six injuries. No fatalities are listed. Those numbers don’t establish that the eBoost system caused every reported incident.

Instead, they’re among the data regulators will examine as they determine whether a safety-related defect exists and whether further action is necessary.

This Is an Investigation, Not a Recall

Owners shouldn’t confuse Engineering Analysis EA26006 with a recall. NHTSA has not announced a recall covering all 1.16 million vehicles, and there is currently no universal free repair associated with the Engineering Analysis.

An Engineering Analysis is a deeper stage of NHTSA’s defect-investigation process and allows regulators to further examine the scope, frequency and safety consequences of a potential problem. The investigation could ultimately close without a recall, or additional findings could lead GM or regulators to pursue further safety action.

Owners can use NHTSA’s recall lookup tool to check whether their individual VIN has any existing open recalls, but an investigation won’t necessarily appear as a recall simply because a model is included in EA26006.

What Owners Should Do If Their Brakes Feel Different

Drivers of vehicles included in the investigation should pay attention to changes in brake feel and dashboard warnings. A hard brake pedal, “Service Brake System” message or illuminated brake and ABS warning lights shouldn’t be ignored. Someone experiencing an apparent braking problem should prioritize getting the vehicle safely off the road and having the condition evaluated rather than continuing to drive normally.

Owners who experience a potential safety problem can also file a complaint with NHTSA. Consumer complaints are one of the sources regulators use to identify possible defect trends.

From a financial standpoint, owners should also keep repair orders, diagnostic reports, towing receipts and other documentation connected with a suspected brake-system problem. There is no guarantee those expenses will be reimbursed, but records could become important if a recall, warranty action or other manufacturer remedy is eventually announced.

For now, the key distinction is that NHTSA is investigating a potential problem across more than 1.1 million vehicles—not announcing that all of those vehicles are defective or recalled.