Certain Santa Fe Hybrid (TM HEV) and Tucson Hybrid (NX4 HEV) vehicles may exhibit a restricted coolant...

Bulletin number

25-01-065H TSB (T9L)

Component

Engine

Summary

Certain Santa Fe Hybrid (TM HEV) and Tucson Hybrid (NX4 HEV) vehicles may exhibit a restricted coolant flow condition, which may be accompanied by a warning message (e.g., Coolant Supplement, Refill Inverter Coolant) in the cluster. No related DTCs are stored, and coolant level is normal in the reservoir tank. The coolant flow may be restricted by debris, causing abnormally high Electric Water Pump (EWP) speed. This TSB contains instructions for confirming high RPMs in the EWP, then using the Coolant Flushing Equipment Set to flush and clean debris from the various cooling system circuits. The existing blue coolant, Electric Vehicle Battery System Coolant (BSC-2), will be used to flush the system. Then the coolant will be replaced with new pink coolant (LLC-10).

Owners of these vehicles have filed 63 complaints in the engine category.