The Office of Defects Investigation (ODI) opened PE21-016 on July 7, 2021, to investigate 364 complaints alleging that one or both sliding doors on 2016 Model Year (MY) Grand Caravan or Town and Country vehicles could not be opened. The door(s) could not be opened using the mechanical handle or electronic remote switches. Many of the complaints described having to remove passengers seated in the rear of vehicles through the front doors, the second sliding door (if it was operational), the window, or the car?s rear hatch. The complainants have expressed concerns that if the sliding door(s) cannot be opened in the event of an emergency or crash, it could trap passengers or delay their egress.On June 4, FCA published TSB# 23-017-20 instructing dealers to replace the door lock actuator instead of the entire door latch assembly on the subject vehicles when consumers complained about either one or both of the sliding door locks not functioning and/or emitting a loud buzzing noise during lock/unlock operation. On June 16, 2021, FCA approved a Quality Warranty Extension for fifteen years/150,000 miles from the vehicle's in-service date for sliding door lock actuators on vehicles built between May 1, 2015, through January 9, 2017. FCA has started notifying owners about the new program. FCA will provide reimbursement for owners who previously paid for sliding door repairs.Consumers whose sliding doors are inoperative will have the opportunity to have their vehicle diagnosed, and if a fault is identified, have the sliding door actuator repaired at no charge.Analysis of the FCA IR response and ODI complaint data found that the majority (96%) of sliding door failures occurred prior to the calendar year 2020 when the subject vehicles had approximately 4 years in service. At the time of the closing of this investigation, 99% of the subject vehicles are passed the age where failures typically occur. The number of new reports has been decreasing since 2020 and further reduced following the FCA Warranty Extension program. ODI found that prior to a failure of the sliding door(s) there is normally a loud buzzing noise/sound generated that alerts the operator to the actuator starting to wear out.ODI has not identified any crashes or injury allegations due to the sliding door being inoperable on the subject vehicles following nearly six years of exposure. ODI will continue to monitor complaints received for the incidence of sliding doors becoming inoperative.Accordingly, the investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist, and the agency reserves the right to take additional action if warranted by new circumstances.For a complete summary of this investigation and related consumer complaints, please see attached closing resume document.