Technical Service Bulletin 21-045-25 — 2026 RAM 4500
POWER TRAIN
Bulletin Details
| TSB ID | 21-045-25 |
| Manufacturer | |
| Vehicle | 2026 RAM 4500 |
| Component | POWER TRAIN |
| Communication Date |
Bulletin Summary
Flash: Transmission Control Module (TCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must 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. The customer may describe one or more of the following: ● Vehicle stuck in default gear, and possibly stranded for many minutes. ● Rough or bumpy 2-3 power on upshifts and/or 3-2 coast down shifts. ● Vehicle enters into limp home mode. In addition, the following software enhancement is available: ● Decreased sensitivity to DTCs P1D8A and P1D8 This bulletin involves reprogramming the TCM with the latest available software.
About Technical Service Bulletins
A Technical Service Bulletin (TSB) is a document issued by a vehicle manufacturer to its dealers, describing a known issue with a specific vehicle or set of vehicles and the recommended procedure to fix it. Unlike recalls, TSBs are not mandatory and are typically only performed if an owner reports the related issue. However, TSBs can be an indicator of common problems with a vehicle.
Other TSBs for the 2026 RAM 4500
18-012-26 REV.A
ENGINE
18-012-26 REV.A
ELECTRICAL SYSTEM
18-012-26
ELECTRICAL SYSTEM
08-020-26
SERVICE BRAKES
18-002-26
POWER TRAIN
21-006-26
POWER TRAIN
S2523000088
ELECTRICAL SYSTEM
108409
UNKNOWN OR OTHER
08-323-25 REV. A
ELECTRICAL SYSTEM
S2508000090
ELECTRICAL SYSTEM