{"nhtsa_id":10139655,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2018-06-11","date":"2014-04-30","document_id":"21-017-14","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM; POWER TRAIN","mfr_system":null,"summary":"Flash: Transmission Shift Enhancements This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) and Transmission Control Module (TCM) with new software. NOTE: Both the PCM and TCM must be up to date for these changes to be effective. The customer may indicate that they are not satisfied with the shift quality of the transmission. Improvements to the transmission calibration have been made to the following: Upshift Improvements ? Shift quality in Normal Mode ? Shift quality in Sport Mode ? Shift inhibit while transitioning in/out of MDS Downshift Improvements ? Downshift quality while accelerating ? Downshift quality while coasting General Improvements ? Torque converter clutch control during interlocked downshifts ? Torque converter clutch control during accelerator pedal tip in/out ? High speed gear hunting (shifting back/forth repeatedly between two gears) ? Allow 3rd gear launch at high altitude while in Snow Mode ? 2nd gear launch quality in ECO mode","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2014/MC-10139655-9999.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2014/MC-10139655-0001.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10139655","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":2014,"year_to":2014,"match":"exact","vehicle_ids":["2014_jeep_grand-cherokee"]}],"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":[]}