2026-07-21 · 4 min read
Toyota Yaris Hybrid Inverter Coolant Guide
Yaris hybrid has a separate inverter cooling circuit — different from the engine coolant. Change Toyota Genuine Inverter Coolant every 80,000 km or 4 years.
Yaris Hybrid Inverter Coolant — Easy to Miss, Important to Do
The Yaris Hybrid power control unit (PCU) converts DC battery power to AC for the drive motor — and generates heat in the process. The inverter coolant circuit keeps the PCU and motor-generators below critical temperature. This coolant is NOT the same as the engine coolant and must not be mixed. Service interval: every 160,000 km or 10 years. Neglecting this leads to overheating of the PCU, which triggers limp mode and eventually PCU failure (replacement cost: RM 8,000–15,000). Cost to flush and replace inverter coolant: RM 150–250.
Hybrid Inverter Coolant — Toyota Malaysia
Toyota hybrid models (Prius, Sienta, Altis hybrid, Alphard hybrid) have a separate inverter cooling system for the power electronics. This coolant must be flushed every 5 years or 100,000 km — it is separate from the engine coolant. Use Toyota Genuine Super LLC (pink) — do NOT mix with generic coolant. Neglecting inverter coolant causes overheating of the power control unit (PCU), which can lead to a RM 8,000–20,000 repair. Check the inverter coolant level monthly (separate reservoir under the bonnet).