{"nhtsa_id":10150548,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2018-12-10","date":"2015-04-21","document_id":"21-027-15","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM; POWER TRAIN","mfr_system":null,"summary":"Flash: Transmission Shift Enhancements This bulletin involves reprogramming of the Transmission Control Module (TCM) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp (MIL) Illumination. Upon further investigation, the technician may find Diagnostic Trouble Code (DTC) P0734 - Gear 4 Shift Incorrect Ratio stored in the TCM memory. In addition, the following TCM calibration improvements are also available for vehicles equipped with the 845RE 8 speed transmission (sales code DFL). These improvements are listed per engine application. 3.0L gas engine (sales code EHD) ? Improved upshift timing. ? Improved torque converter engagement. ? Improved shift timing during tow mode operation. ? Improved shift points during aggressive driving. ? Calibration improvement to correct bump feel during 2-1 downshift. ? Improved shift timing while in snow, base, and hill modes. 3.6L gas engine (sales code ERB) ? Improved 4-3 and 3-2 downshifts. ? Improved shift timing at higher altitudes. ? Improved shift timing while in sand mode. ? Calibration improvement for multi-gear downshift timing during passing maneuvers. ? Calibration improvement for intermittent delayed upshift.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2015/MC-10150548-9999.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2015/MC-10150548-0001.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10150548","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":["P0734"],"topics":[],"vehicles":[{"make":"DODGE","model":"DURANGO","year_from":2015,"year_to":2015,"match":"exact","vehicle_ids":["2015_dodge_durango"]},{"make":"JEEP","model":"GRAND CHEROKEE","year_from":2015,"year_to":2015,"match":"exact","vehicle_ids":["2015_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":[]}