The federal government is expanding a safety investigation into a number of vehicles manufactured by General Motors after receiving hundreds of reports of brake failure. The problem affects more than 1.1 million cars, including many of GM’s electric vehicles, as well as ones it has built for Honda and Acura. The problem is with the brake-by-wire system (which GM calls eBoost), which can suffer a spindle fracture while driving.

GM says that in the event of that happening, the car should still retain a number of critical safety features—antilock brakes, traction control, and stability control—at least until it comes to a complete stop, at which point they become inoperable. But NHTSA’s ODI says that it has received many reports that contradict this behavior and allege that eBoost failures are followed by an immediate loss of braking, which obviously poses a safety risk.

Indeed, NHTSA has received 227 incident reports, a number that grows to 745 once you include the hundreds of occurrences reported to GM. Twenty-two cases resulted in crashes, and while six people have been injured in five crashes, thankfully there have been no fatal incidents.

NHTSA says that the following vehicles are equipped with eBoost: “2023-2026 MY Cadillac Lyriq, Chevrolet Colorado, and GMC Canyon; 2024-2026 MY Buick Enclave, Envision; Chevrolet Blazer EV, Equinox EV, Traverse; Cruise Origin; and GMC Acadia; 2025-2026 MY Cadillac Celestiq and Optiq. ODI is also aware of 2024-2026 MY Acura ZDX and 2024-2026 MY Honda Prologue vehicles that were built with this system.”