The converter/inverter
The converter/inverter in a Toyota hybrid sits up in the engine bay, usually on top of or next to the transmission. It’s the brains of the hybrid system, flipping DC from the battery into AC for the electric motors and back again when regenerating power. It also steps voltage down to run the car’s 12V system.
​
Keeping It Cool – Maintenance Tips
​
This thing gets hot, so Toyota gives it its own liquid cooling system, separate from the engine’s coolant. Here’s what you need to keep it running smooth:
​
-
Coolant Change: Toyota says swap the inverter coolant around 150,000 km, but earlier if contaminated.
-
Use the Right Stuff: Only use Toyota Super Long Life Coolant (the pink one). Don’t cheap out on random coolant—it’s not worth the risk.
-
Check for coolant level at the reservoir, make sure it's between F and L.
-
Pump Health: If you ever get a pump DTC (Diagnostic Trouble Code), replace the pump immediately—don’t wait. A failed pump means overheating, and overheating kills inverters.
Skip this maintenance, and you're looking at a dead inverter—and that’s a pricey fix you don’t want