2018 Volkswagen Tiguan Seat Belt Failure Investigations

On January 10, 2018, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE18001 to evaluate the seat belt separations in certain model year 2018 Volkswagen (VW) Tiguan vehicles. These separations occurred during two New Car Assessment Program (NCAP) tests. The NCAP test is a 35 mph, full frontal, rigid barrier crash with a belted 50th percentile male ATD driver and a belted 5th percentile female ATD front passenger. The 2017 tests were conducted at MGA Research Corporation on December 8th, and at the Transportation Research Center on December 13th. During both crash tests, the driver seat belt webbing completely separated where the webbing passed through the seat belt latch plate slot, a device Volkswagen calls a Crash Locking Tongue (CLT).

Then, on July 3, 2018, the ODI upgraded their investigation and opened Engineering Analysis EA18-005 to further examine seat belt behavior in the subject vehicles and to determine, among other things, a root cause for the seat belt webbing separation. The investigation resume reveals that during both crash tests, the driver seat belt webbing completely separated in tension at the CLT. Based on its analysis of the NCAP test results, and supported by several sled tests, VW asserted that the test dummy umbilical cord exerted additional forces on the seat belt system causing the separation. However, micro analysis conducted by the Materials Laboratory at the National Transportation Safety Board (NTSB) verified the seat belts failed in tension and not due to cuts or abrasion. This Engineering Analysis will allow ODI to perform a thorough review of any vehicle and seat belt design changes for the new 2018 MY Tiguan platform and their effects on the performance of the seat belt system.

The NCAP test reports are not available on NHTSA’s website. Case Study Collision Science’ communication attempts with ODI did not reveal additional information, and requests for the NCAP test reports directed to the Department of Transportation were not acknowledged.

UPDATE: Testing the effect of the CLT on seat belt webbing separation.