Tesla is voluntarily recalling all 90,000 of its Model S sedans in order to examine a possible defect in the vehicles' seat belt assembly, the company said Friday.

The issue concerns the part of the seat belt mechanism that preemptively tightens the seat belt in anticipation of a crash. It was discovered when a passenger in one of Tesla's European sedans turned around in the front seat to address a passenger in the rear seat.

Although the incident did not cause an accident or any injuries, Tesla is sending e-mails to affected customers asking them to bring their vehicles to a company service center for a free inspection. The check should only take a few minutes, the company said.

Tesla told owners Friday it has already checked the seat belt systems in 3,000 Model S sedans, but that it "decided to conduct a voluntary recall as a proactive and precautionary measure."

The move comes exactly a month after Consumer Reports slammed the automaker for a "worse-than-average overall problem rate." Consumer Reports had previously given the Model S a glowing review.

Last month, the company rolled out its highly-anticipated autopilot feature, which enables the Model S to stay within its lane and avoid collisions with other vehicles with little direct human input. YouTube videos have since shown some drivers taking their hands off the wheel or even leaving the driver's seat, leading chief executive Elon Musk to promise new restrictions on the feature.

Meanwhile, Tesla has struggled to weather investor concerns that the company will be unable to meet expectations. High battery costs, rising competition from other automakers and supply-chain issues have all contributed to growing skepticism among business analysts. Tesla shares closed down nearly 1 percent Friday.

Tesla is one of a number of companies developing next-generation automotive technologies. Beyond autopilot, the company has pioneered the concept of using over-the-air software updates to deliver new features to its vehicles, similar to the way smartphones and PCs receive upgrades. Tesla's lane-keeping and crash-avoidance sensors also promise to make car travel safer, and many other automakers have adopted the technology with an eye toward making them a standard safety feature, much like airbags and seat belts.

These and other innovations are likely to help insulate Tesla from any long-term backlash stemming from the recall, said Karl Brauer, an analyst with Kelley Blue Book.

"Tesla’s customer base is hugely loyal to, and passionate about, the brand," said Brauer. "While no car owner likes dealing with a recall, everyone knows they are unavoidable. In Tesla’s case they are starting with a dedicated group of owners, very few of which will care about a recall, particularly one related to ensuring customer safety."