{"nhtsa_id":10189784,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2021-04-03","date":"2021-03-18","document_id":"TSB 21-2076","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"Some 2013-2018 F-150 vehicles equipped with electronic shift on-the-fly (ESOF) 4-wheel drive (4WD) may exhibit an intermittent grinding noise while driving in 2-wheel drive (2WD) mode most commonly on acceleration. ESOF can be identified as it does not have a 4WD AUTO (4A) position on the mode selector switch (MSS). This may be due to a loss of vacuum to the integrated wheel end (IWE) actuators and/or wear of the IWE components. To correct the condition, follow the Service Procedure steps to reprogram the transfer case control module (TCCM) and replace any worn vacuum and/or IWE components.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10189784-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2021/MC-10189784-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10189784","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"FORD","model":"F-150","year_from":2013,"year_to":2018,"match":"exact","vehicle_ids":["2013_ford_f-150","2014_ford_f-150","2015_ford_f-150","2016_ford_f-150","2017_ford_f-150","2018_ford_f-150"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}