2026-07-21 · 4 min read
Toyota Prius Inverter Coolant Guide Malaysia — Critical Maintenance
Prius inverter coolant is the single most overlooked maintenance item. Neglect causes an inverter failure costing RM 8,000–15,000 in Malaysia.
Prius inverter (power control unit / PCU) converts battery DC to AC for the motor. The inverter runs hot — it has a dedicated water-cooling circuit separate from the engine cooling. The smaller reservoir under the bonnet is the inverter coolant.
Inverter Coolant Service
- Check level every 10,000 km — low inverter coolant causes P0A93 / inverter overheat fault code
- Change every 4 years (same as engine coolant) — use Toyota SLLC only
- Inverter coolant pump (electric): replace at 150,000 km if not already done — RM 300–500