The National Highway Traffic Safety Administration (NHTSA) is reviewing an increasing number of complaints submitted by Tesla owners about their vehicles unexpectedly slamming on the brakes.
At least 107 complaints about so-called "phantom braking" events in Teslas were filed to the agency in the past three months, up from 34 in the previous 22 months, The Washington Post first reported this week.
"NHTSA is aware of complaints received about forward collision avoidance and is reviewing them through our risk-based evaluation process," NHTSA said in a statement.
"If the data show that a risk may exist, NHTSA will act immediately."
Tesla was forced to recall and update an optional beta version of its Full Self-Driving system software being tested by approximately 12,000 owners last October due to a similar issue, but all Teslas are equipped with an automatic emergency braking system. The current review is not at the level of an official investigation at this stage.
The automaker last year eliminated the use of radar in its electronic driver aids, opting to rely on a "pure vision" method to monitor the road through cameras located around the vehicles.
Tesla this week updated the Full Self-Driving beta software in the nearly 54,000 cars now running it to remove a feature that allowed them to roll past stop signs without coming to a complete stop if there were no other vehicles or pedestrians in the area.
Tesla no longer operates a communications office to provide comment to news organizations, and CEO Elon Musk has not publicly discussed the latest phantom braking issue.