{"nhtsa_id":10172128,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2020-03-05","date":"2020-02-07","document_id":"TSB_TRA088","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"TECHNICAL SERVICE BULLETIN: TRANSMISSION CONTROL UNIT (TCU) GEAR SHIFT LOGIC IMPROVEMENT - This bulletin provides the procedure to improve the gear shift logic of the Transmission Control Unit (TCU) on some 2018MY Optima (JF, JFa) vehicles produced from April 18, 2017 through July 11, 2018, equipped with 2.0L T-GDI and 2.4L GDI engines, which may harsh downshifts (including 2-1 gear change).","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2020/MC-10172128-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2020/MC-10172128-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10172128","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"KIA","model":"OPTIMA","year_from":2018,"year_to":2018,"match":"exact","vehicle_ids":["2018_kia_optima"]}],"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":[]}