The National Highway Traffic Safety Administration is investigating how electric car maker Rivian services its vehicles’ rear suspension components, after receiving two reports from owners who lost control of their cars while driving.

The federal safety regulator’s Office of Defects Investigation (ODI) said on Thursday that both vehicles had been previously serviced, one of which had been in a collision before the work was done. According to the ODI, Rivian first realized in March 2025 that the rear toe link — a critical part of the suspension that helps keep the wheel straight — had a “sensitivity to service procedures,” causing the company to update how it handled the part during service and repairs.

The ODI’s investigation will look into how and why the rear toe link on Rivian’s R1 vehicles is sensitive to “foreseeable road and service conditions,” compare the two failures submitted by owners, evaluate Rivian’s current toe link repair procedure, and assess the condition of other 2023-2024 model year R1 vehicles.

Nearly 115,000 vehicles could be affected, the ODI said.

Rivian in January 2026 recalled almost 20,000 vehicles to include those that had received the toe link service “prior to the March 2025 improvement,” according to the ODI.