RAM 2500 2025–2026 — technical service bulletin
Bulletin 08-171-26 · NHTSA communication 11031666 · issued Apr 21, 2026
Technical service bulletin
communication type
Unknown OR Other
component
2025–2026
model years
8
vehicle entries
Official summary
Loss Of Cabin Heating 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): ● U0615 - Lost Communication With Engine Coolant Bypass Valve "A". ● U11E9 - Lost Communication With AGS. Customer may also comment on the following: ● Loss of cabin heating This bulletin involves applying grease to the 3 way valves wire harness connector or, if necessary, the replacement of both the wire harness and the 3 way valve
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.