The contact owns a 2016 Toyota Sienna. The contact stated the driver-side sliding door latch failed to latch as intended. The contact stated that after several attempts, the sliding door failed to close completely. The contact stated that no warning light was illuminated. The vehicle was taken to an independent mechanic but was not diagnosed. However, an unknown part was repaired. The contact stated that the failure persisted. The contact removed the button under the sliding door to manually close the door. The manufacturer was not notified of the failure. The contact related the failure to NHTSA Campaign number: 16V858000 (STRUCTURE); however, the VIN was not included. The failure mileage was approximately 70,000.