{"nhtsa_id":11023318,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-09-24","date":"2025-09-17","document_id":"21-027-25 REV. A","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","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):** ● **P0827-00 Up and Down Shift Switch Circuit Low. ● P0826-00 Up and Down Shift Switch Circuit. ● P085F-00 Up and Down Shift Switch Circuit Range/Performance.** ● P1DCD-00 - TCM Monitoring Processor Performance Multiple Clutches Locked Up. Customers may also experience one or more of the following: ● **Vehicle stuck in default gear, and possibly stranded for many minutes. ● Rough/bumpy 2-3 power on upshifts and/or 3-2 coast down shifts.** ● Vehicle enters into limp home mode. **Other software improvements: ● Decreased sensitivity to faults P1D8A and P1D8B.* This bulletin involves inspecting the TCM software level and possibly reprogramming the TCM with the latest available software","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023318-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023318-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11023318","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["P0826","P0827","P085F","P1D8A","P1D8B","P1DCD"],"topics":[],"vehicles":[{"make":"RAM","model":"2500","year_from":2025,"year_to":2025,"match":"exact","vehicle_ids":["2025_ram_2500"]}],"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":[]}