The National Highway Traffic Safety Administration has opened an investigation into approximately 115,000 Rivian electric vehicles following reports of rear suspension failures that caused drivers to lose control of their vehicles.

The probe focuses on critical suspension component failures in Rivian's R1 model vehicles. At least two owners have reported losing control of their vehicles after a suspension part broke, according to regulatory filings. In both documented cases, the affected vehicles had undergone previous servicing.

The investigation covers Rivian's R1T pickup trucks and R1S SUVs, representing a significant portion of the electric vehicle startup's delivered fleet. The company has been working to establish itself in the competitive electric truck market since going public in 2021.

Rivian has not immediately responded to requests for comment regarding the federal investigation. The NHTSA probe will determine whether the suspension failures represent a systemic safety defect requiring a formal recall.

The investigation comes as electric vehicle manufacturers face increased scrutiny over safety and quality issues as production scales up across the industry.