Land Rover Defender 2023–2024 — technical service bulletin
Bulletin TUCC_MAR2026_18 · NHTSA communication 11030959 · issued Mar 13, 2026
Technical service bulletin
communication type
Engine
component
2023–2024
model years
6
vehicle entries
Official summary
Coolant may leak from the turbocharger coolant hose O-rings, resulting in engine coolant escaping into the engine compartment and subsequent illumination of the low coolant warning indicator on the instrument cluster. Replacement coolant hose O-rings are required.
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.