"The complaints allege braking incidents, some with large speed changes, occurring with nothing obstructing the vehicles path," according to a document posted Thursday to NHTSA's website.
The agency opened the investigation Monday.
Six of the complaints allege a collision with minor injuries, according to the report. The complaints also allege the inadvertent braking happens without warning.
"Twice in the past six months, driving down our rural road to our neighborhood, the car flashed the 'brake' sign on the dash and applied the brakes," one complaint reads. "After touching the brake pedal, the car returned to its normal speed. The road was clear, with no obstructions, no cars in front or cars [from] coming the other direction."
In a statement to Automotive News, Honda spokesman Chris Martin said the automaker is aware of the investigation and committed to safety.
“Honda will cooperate with the NHTSA through the investigation process, and we will continue our own internal review of the available information,” Martin said.
Automakers in recent years have installed automatic emergency braking as standard equipment on newer vehicles. At least 12 automakers, including Honda and its luxury brand Acura, have installed the crash-avoidance technology on more than 95 percent of the vehicles they produced in 2020 and 2021 as part of a voluntary commitment led by NHTSA and the Insurance Institute for Highway Safety.
By 2024, NHTSA expects to initiate a rule-making to mandate automatic emergency braking and pedestrian automatic emergency braking on new passenger vehicles — a requirement in the infrastructure law passed by Congress last year.
Similar probes
NHTSA last week opened an investigation into certain Tesla vehicles for a similar problem.
The safety probe covers an estimated 416,000 Tesla Model 3 and Y vehicles from 2021-22 that are equipped with the automaker’s Autopilot advanced driver-assistance system. Complaints allege that while using Autopilot's features, such as adaptive cruise control, "the vehicle unexpectedly applies its brakes while driving at highway speeds," according to the agency's report.
In 2019, NHTSA also launched an investigation into potential unintended braking in 675,000 Nissan Rogue crossovers from the 2017-18 model years after reports alleging the automatic emergency braking system can engage unexpectedly.
NHTSA's process
With a safety probe, the agency will assess the scope and severity of the potential defect and other possible safety-related issues.
Most NHTSA investigations start as preliminary evaluations, in which agency engineers request information from the manufacturer, including data on complaints, injuries and warranty claims. The manufacturer also can present its view regarding the alleged defect and may issue a recall.
After the evaluation, NHTSA will either close the investigation or move into the next phase. If a safety-related defect exists, according to NHTSA, the agency might send a "recall request" letter to the manufacturer.