Tesla has since sought to remedy the issue at that intersection, the agency said.
Full self-driving, which has been marketed under the terms full self-driving (supervised) and full self-driving beta, is Tesla’s most sophisticated advanced driver-assistance system.
It enables vehicles to manoeuvre around city and residential streets, making lane changes and steering on their own, though drivers are expected to maintain full attention.
Tesla chief executive Elon Musk has positioned it as crucial to the company’s ambitions, describing the technology as “the difference between Tesla being worth a lot of money and being worth basically zero”.
Tesla and Musk did not immediately respond to a request for comment.
The agency said its investigation aimed “to assess the scope, frequency, and potential safety consequences of [full self-driving] executing driving manoeuvres that constitute traffic safety violations”.
Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.