Certain Santa Fe Plug-in Hybrid (TM PHEV) and Tucson Plug-in Hybrid (NX4 PHEV) vehicles may exhibit a...

Bulletin number

25-01-064H TSB (T9F)

Component

Engine

Summary

Certain Santa Fe Plug-in Hybrid (TM PHEV) and Tucson Plug-in Hybrid (NX4 PHEV) 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 coolant will be replaced with the updated Electric Vehicle Battery System Coolant (BSC-2) low-conductivity blue coolant.

Owners of these vehicles have filed 9 complaints in the engine category.