RAM 2500 2025 — technical service bulletin
Bulletin 9100525 · NHTSA communication 11015963 · issued Mar 26, 2025
Technical service bulletin
communication type
Electrical System
component
2025
model years
4
vehicle entries
Official summary
"Base led headlamp RT 25 MY HDCC Ignition DTC (U300A-29 Ignition Switch - Signal Invalid) in stored state for SLML and SLMR. All headlamps on the Heavy Duty with SW 24.43.00(Premium) or 24.44.00(Base) will show a U300A-29 -> Ignition Switch-Signal Invalid as a stored DTC. If you experience this condition, please clear the DTCs on SLML and SLMR once and restart the truck and check if the DTC is in active state 10 seconds after the engine is turned ON, check the hardware ignition line and repair as required. If the DTC reappears as stored DTC (See Figure 1), no repair is required. The headlamps
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.