For those with access to a Toyota scanner or an aftermarket (I use Snap-on) or if your friendly neighborhood tech (we called ourselves mechanics in my day...) has a pro level scanner, this is an easy project that will take 30 to 45 minutes.

Hybrid01.jpg

Start off by removing the coolant tank cap under the hood.

Hybrid02.jpg

The drain plug is noted here looking underneath the car. Drain the coolant into a bucket and make sure you capture all of it. It needs to be measured later.

Hybrid03.jpg

Like the transaxle, use a 10mm hex bit socket to remove this plug and if you have one of your new spare 18mm crush washers from the transaxle change, you can use it here. Once drained, replace and torque this fill plug to 29 ft-lbs. Don't forget your new crush washer....



As noted above, pour the coolant you removed above into a clean container and mark the level on the side. Pour the used coolant onto your disposal container and fill to the mark you made with new, Toyota super long life coolant (pink). Pour as much of this as you can into the coolant tank under the hood. The system will gurgle and burp while you are doing this as it gets rid of some air.

Hybrid05.jpg

You will now need a bi-directional scanner hooked up. The picture above is the Hybrid System options for a Snap-on Modis (other scanners will be similar). Select "Actuator Tests"

Hybrid06.jpg

Select "Water Pump (OFF/ON"

Hybrid07.jpg

With "YES" highlighted, press select on the scanner to start the pump. Add coolant while the pump is running and purging the air from the system. This will only take 60 seconds or so and you can listen to the sound of the pump to know when the air is purged.

Hybrid08.jpg

Move the cursor to highlight "OFF", press select and exit your scanner.

Hybrid09.jpg

Back under the hood, top off the tank and replace the cap. You have now changed the hybrid invertor coolant.

Total cost was $21.81 plus tax for a gallon of Toyota Super Long Life Coolant (with coolant left over) and 30 to 45 minutes of time. If you don't have a scanner, ask your local tech to do this for you. He might charge you $50 +/- to run the pump actuator test.

 

Thanks for the writeup, GeorgiaHybrid! I was able to change my inverter coolant without problems.
By the way, I used this cable to run the inverter pump:

http://www.uobd2.com/wholesale/mini-...able-2442.html

The cable paid for itself off and in addition, I was able to turn off that annoying seatbelt chime.

 

Modifying BCM options is the main reason I am on the hunt for a Techstream. I have been waiting for the aftermarket scanners to do that but so far, nothing.....

 

Did you buy the license key for the techstream software or is it free (the downloadable version)?

 

I am not sure whether it is "legally" free or not, but it the techstream software IS included with the cable. The cable is shipped from china and took about 10 days to get here (Kansas City) but everything needed to diagnose/change settings in your toyota is included!

On that link above, click on it, then click on "tech support" and it even includes the link to download the software too. (the CD included with the package is one of those mini CDs that will get stuck in a laptop slot loading DVD drive)

 

sweet deal! Thanks for the link.
Which part of KC do you commute? I live close to KCI airport and work downtown. I might probably have seen you driving around (lots of TCH now in Kansas City)

 

Nice! I live around the city market area and go to school at UMKC's hospital hill campus.
Aren't you glad that the broadway bridge is now open again? Yet 6 months later...downtown is a mess again with all of the highway closures!!

 

After draining the inverter cooling system and refilling it again, why can't I run the water pump by starting the engine, instead of using Techstream? From what I read, the pump will stop after 5 seconds if there isn't enough coolant. What is the danger of filling the inverter coolant system, running the engine, refilling again, and restarting the car again. It seems as though you are achieving the same result, which is turning on the water pump to get rid of any pocket air in your inverter cooling system.

 

If the engine is running, the inverter is powering the systems in the car. If you have any air bubbles inside the converter, you have the potential for a hot spot and a burned up inverter. It's not worth the chance for that happening from my viewpoint but each of us has a different risk level we are willing to take.

The odds are, nothing will happen. With me however, I find that Murphy's Law has an optimistic view on life......It WILL go wrong, each and every time.... I happen to have the equipment at my home garage, I enjoy working on my cars so they never get worked on anyplace else and I am very **** about the way things are done.

 

Georgia, thanks for your reply. You seem very knowledgeable, and I was wondering if you or anyone else can help me out.

My 07 TCH has 165,000 miles on it, and I noticed that the inverter coolant is leaking. Please see picture.

Do you think I can just drain the inverter coolant, open up that plate, and reseal it? What is behind that plate that is leaking out inverter coolant? What do you recommend that I should do?

TIA.