{"vehicle":{"id":"2025_ram_4500","year":2025,"make":"Ram","model":"4500"},"code":"P1D8A","generic":false,"description":null,"bulletins":{"as_of":"2026-10-19","count":4,"bulletins":[{"nhtsa_id":11032327,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-05-06","date":"2026-05-01","document_id":"21-028-26 REV. A","mfr_campaign":null,"component":"POWER TRAIN","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): ● P0826-00 - Up/Down Shift Switch. ● P0827-00 - Up/down Shift Switch Circuit Low. ● P085F-00 - Up And Down Shift Switch Circuit Range/performance. Customers may also experience one or more of the following: ● Customer is unable to switch the ignition to OFF when in Park gear. ● After shifting into Park, the Instrument Panel Cluster (IPC) will display that the transmission is in Neutral. NOTE: The transmission will actually be in Park and able to hold the vehicle, but the cluster display would indicate Neutral, preventing the engine from shutting off. ● 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 DTCs P1D8A and P1D8B. This bulletin involves inspecting and if required reprogramming the TCM with the latest available software","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032327-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032327-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11032327"},{"nhtsa_id":11027628,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-01-14","date":"2026-01-08","document_id":"21-002-26","mfr_campaign":null,"component":"POWER TRAIN","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): ● P0826-00 - Up/Down Shift Switch. ● P0827-00 - Up/down Shift Switch Circuit Low. ● P085F-00 - Up And Down Shift Switch Circuit Range/performance. Customers may also experience one or more of the following: ● **Customer is unable to switch the ignition to OFF when in Park gear. ● After shifting into Park, the Instrument Panel Cluster (IPC) will display that the transmission is in Neutral.** NOTE: **The transmission will actually be in Park and able to hold the vehicle, but the cluster display would indicate Neutral, preventing the engine from shutting off.** ● 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 DTCs P1D8A and P1D8B. This bulletin involves reprogramming the TCM with the latest available software.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027628-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027628-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11027628"},{"nhtsa_id":11023605,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-10-02","date":"2025-09-26","document_id":"21-039-25 REV. A","mfr_campaign":null,"component":"POWER TRAIN","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. 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 reprogramming the TCM with the latest available software.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023605-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023605-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11023605"},{"nhtsa_id":11023325,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-09-24","date":"2025-09-18","document_id":"21-039-25","mfr_campaign":null,"component":"POWER TRAIN","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. 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 reprogramming the TCM with the latest available software.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023325-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11023325-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11023325"}],"url":"https://open.wenmarpro.com/makes/ram/4500/2025/bulletins?code=P1D8A"},"related":{"components":[],"bulletins":[],"recalls":{"may_apply":true,"recalls":[],"lookup":{"nhtsa":"https://www.nhtsa.gov/recalls","tc":"https://wwwapps.tc.gc.ca/Saf-Sec-Sur/7/VRDB-BDRV/search-recherche/menu.aspx?lang=eng","maker":null}}},"url":"https://open.wenmarpro.com/makes/ram/4500/2025/codes/P1D8A","note":"The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.","attribution":["Contains information licensed under the Open Government Licence – Canada."]}