{"nhtsa_id":11027640,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-01-14","date":"2026-01-10","document_id":"21-009-26","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"Flash: Transmission Control Module (TCM) Updates *Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):** ● P0979-00 - Shift Solenoid 3 Control Circuit Low. ● P0219-00 - Engine Overspeed Condition. ● P0731-00 - Gear 1 Shift Incorrect Ratio. **Customers may experience the following: ● Shift shudder and shift shock during wide open throttle, high clutch energy shift.** The following software update is also included: ● Improved high RPM in coasting situations for the 1-2 shift This bulletin involves reprogramming the TCM with the latest available software.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027640-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027640-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11027640","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":["P0219","P0731","P0979"],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":2018,"year_to":2018,"match":"exact","vehicle_ids":["2018_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":[]}