2026-07-21 · 4 min read
Toyota Sienta Inverter Coolant Guide Malaysia (Hybrid)
Neglecting Sienta hybrid inverter coolant causes costly overheating damage. Maintenance schedule and warning signs explained.
NHP170 Sienta hybrid inverter coolant is a separate circuit from the engine cooling. Check the smaller secondary reservoir under the bonnet every 20,000 km. Use Toyota SLLC pink — same fluid as engine coolant, separate circuit.
Inverter Coolant Details
- Change inverter coolant every 4 years — same interval as engine coolant; do both at same service
- Low inverter coolant: hybrid power reduction and inverter fault code — check level before assuming inverter failure