NHTSA rejects VW's excuse for Tiguan seatbelt failures

The driver seat belt webbing completely separated from the latch in two separate crash tests.

The National Highway Traffic Safety Administration has upgraded its investigation into seat belt failures that occurred during a series of Volkswagen Tiguan crash tests.

The seat belt webbing completely separated from the latch loop in two separate 35-mph full frontal impacts into a rigid barrier, conducted in December as part of the government's New Car Assessment Program.

VW asserted that the dummy umbilical cord exerted additional forces on the seat belt system. The company conducted several sled tests to support its theory.

After reviewing VW's sled tests, with help from the Materials Laboratory at the National Transportation Safety Board, the NHTSA has concluded that the seat belts "failed in tension and not due to cuts or abrasion."

The agency is now pursuing an engineering analysis to determine a root cause for the belt separation.