NHTSA Complaint #11660473 — 2024 KIA EV9

What happened? While driving at highway speeds (approximately 60-75 mph), the vehicle exhibits a pronounced up-and-down motion at the rear, commonly referred to as “porpoising.” This motion is especially noticeable when traversing uneven road surfaces or expansion joints. This issue compromises vehicle stability and passenger comfort, posing a potential safety risk during high-speed travel. The problem has been consistently reproducible under similar driving conditions. The vehicle has not yet been inspected by a dealer or independent service center for this specific issue. No warning lights or error messages have appeared on the dashboard in relation to this problem. Component suspected: Rear suspension system (exact cause UNKNOWN). I am willing to have the vehicle inspected upon request.