The coolant for the inverter/converter and hybrid transaxle system is a routine maintenance item for hybrid owners. CARspec had the opportunity to replace the coolant for the owner of a 2006 Highlander hybrid today and wanted to share some of the quirks of the system, mainly the bleeding of air from the system after refilling.
The drain for the hybrid coolant is located on the bottom of the hybrid transaxle – it is a 10mm allen. There is an additional drain on the front radiator assembly as well – the hybrid system on this 3.3 liter V6 hybrid drive system has a separate radiator for the engine and hybrid drive components. Here it is circled at the bottom of the photo, the upper radiator grill removed:
Hybrid radiator
Once all the coolant is out from both drains close them and open the air bleed on the radiator, as seen above. When filling the hybrid cooling system this is crucial to help get as much air out of the system before you run the vehicle. You can then fill the reservoir:
Inverter coolant bleeding
Shown above are both the engine and hybrid cooling systems being bled of air. CARspec uses Toyota’s Techstream diagnostic software to run the hybrid system’s water pump for a time until there is no audible gurgling sound. This indicates (combined with strong coolant flow in the reservoir next to the inverter/converter) that all of the air is bled out of the cooling system. On this vehicle the engine’s cooling system was bled of air only after the hybrid cooling system was confirmed air-free to minimize the change of an overheating hybrid system.
As Eden Prairie and Chanhassen’s independent Toyota and Lexus repair specialist we’re happy to offer this routine maintenance item most auto mechanics aren’t familiar with. Using Toyota genuine coolant and factory repair procedures, tools and software, CARspec can take care of any of your hybrid needs. Call us at (952)426-4798 to make an appointment today!
2006 highlander hybrid need to change the 120 A fuse, how to take the fuse box to unbolt it?
Hello!
If a high amperage fuse like your 120amp fuse has failed, there is a major short in the associated system. I would recommend having the vehicle checked out before you spend the money on a new fuse, only to potentially have it fail again.
Be warned that the hybrid high voltage system can be lethal, so be careful!
John
battery charger hooked up back words . son got spark, then nothing. I’ve disconnected 12v battery , disconnected , 288v battery, waited 24 hours. open front of fuse box ,freed cables for free play , can’t pop junction block from housing box. there has to be a easy trick to it or what? also I’m a certified A&P mechanic #2071164..
Jim,
If it is the main 120amp in the underhood junction block, you need to disassemble the fuse block in the car to get to the two bolts that secure the fuse. It looks like this when removed (this is a 140 amp, but the same design): http://carspecmn.com/?attachment_id=1447
The holes at the bottom are where the securing bolts go through. To do so you need to disengage the clips around the perimeter of the fuse block to get enough free play in the block to unbolt the fuse.
Thanks ,been there, done that and it’s the 120A fuse that’s blown, and only this fuse that’s blown. dealer wants $194 labor +$14 for the fuse. + towing. That’s BS ,i’ll rip this bastard apart my self. I’ve wrenched on commercial air craft all my life and this fuse is not going to deft me. thank’s for your time. jim
Good morning Sir, I have an issue with my 2006 Toyota Highlander hybrid, there was a message on messages center say CHECK HYBRID SYSTEM, I did the diagnosis and extracted code P0A05 meaning inverter coolant pump failure. I got a new pump installed it, replaced the coolant, bleed it, then the warning left, only for it the return while driving, I scanned it and got the same code, but I noticed that when the car is on READY the pump works but once the engine comes on, it shuts down and the warning come on again. What do I do next.