Back in February, received a light and discovered that the inverter coolant reservoir was empty. I refilled the reservoir and cleared the code. Today, only 3 months later, the same thing happened. I don't see any wet hoses, puddles, or obvious signs of leakage. Any idea where all my coolant is going? What steps should I use to properly troubleshoot
I suggest you need to carefully inspect the inverter, transaxle, coolant hoses, and the radiator, to look for a pinkish stain which would be evidence of a coolant leak. If you cannot find a leak, an alternative explanation would be that the coolant is leaking into a crack within the transaxle coolant passages, and diluting the transaxle ATF.
you might not see anything wet, just a white or pinkish powder where the coolant leaked and dried up.
UPDATE: I found a leak coming from the transaxle unit near the axle. It had gotten much worse over the past week to a point where it was a steady drip and easy to locate. The coolant reservoir would empty itself within 24 hours. I took it to the dealership and they called me back within an hour. They need to replace the entire inverter, part is about $4000, that doesn't include labor. Fortunately, he said it was covered by Toyota hybrid warranty. Car only has 50k miles so I am surprised by this.
Very interesting. I assume you know the transaxle and inverter are separate components. So apparently the leak you found really originated in the inverter and dripped onto the transaxle, causing you to think the transaxle was the leaking component? You are lucky the transaxle is not the leaking component since that is covered by the 5 year/60K mile warranty which I assume has expired by now for your vehicle.
Yes, the transaxle was my initial thought since that it where I perceived it coming from. They didn't say anything about the transaxle on the phone so here's to hoping it's OK. I am grateful for the 100k Toyota Hybrid Warranty Coverage. I only found 1-2 other instances on the interwebs of this issue so I have to assume it's pretty rare.
