Dreaded P0A80 Code - Car Running / Charging Good.

Mixing coolant is not good. You run the risk of it jelling up, and not flowing.
But it's done.
If you fill it slowly, and a little at a time, you won't have to worry about air pockets because the coolant
will push it out.
If the coolant temperature is within specs, while driving, it's likely working correctly.

 

Yes there is a good flow entering from the top reservoir hose once the thermostat opens. Flow before the thermostat opens uses the thermostat bypass inlet. Even after the thermostat opens a majority of the flow returns via the big radiator hose.

Regardless there is a decent flow through the reservoir after the thermostat opens.

Due to the somewhat opaque plastic of the reservoir, I place a small led flashlight directly on the top of the reservoir to light up the inside, making the flow clearer.

A portion of the gen3 coolant flows (edited from a slightly different gen4 diagram)

 

nasty!

How fast if flows is hot it is and how much it need to cool.
It circulates mostly to the radiator, so you won't see a lot of movement in the coolant tank.
You might as well change the inverter coolant. It's the same coolant. Quicker and easier to change.

 

Yea, the inverter's not important......

Why would you disconnect the battery to do the brakes??? No reason too.
Just do NOT open the drivers door while you're working on them. And keep the key fob more than
20 feet away from the car.

I've replaced the rear pads a few times and the hubs and didn't disconnect the battery.
If you think a family member or friend might open it, put a note on the window and down across
the door handle that says DO NOT OPEN.....

 

As long as you do NOT open the drivers door, you will not have a problem.
If you open the door, the pump will activate and push the puck out if you don't have the pads in
and on the rotor.
It won't hurt to disconnect the 12v battery, but you don't have too.
You will have to rotate the puck to get it all the way back in for the new pads to work.
Make sure you align the pucks to the pins from the pad to fit in the slots or you'll have an angled pad
and rapid uneven wear.

 

When the pump activates, it puts pressure into the storage accumulator. There is always supposed to be pressure there, and the pressure there never pushes on any puck, except when the brakes are applied. If it did, the brakes would be constantly dragging.

However, a gen 3 also does a brake self-test, 90 seconds after shutting down. That self-test does apply pressure to the brakes, and will push any puck out if the pads and rotor aren't there to restrain it.

 

That's good. Check the backing plate/dust shield. It is easily bent....

 

You can try this:

 

While the confirmation pattern mentions Techstream, by looking at the steps in the procedure, you can see that what you need is any capable scan tool able to view and clear codes for the hybrid system, and to display the traction battery state of charge so you can know when it is below 30%.

If you don't already have any such scan tool, there are threads here that can help you select one. You could also seek help from someone who has one.

 

You do have to follow the procedure exactly even if a step seems unnecessary.

Part of the procedure is a forced discharge of the hv battery to 30% which is low. Effectively a stress test. It is worth a try since it does not require a long multi day period of good battery performance to clear the battery permanent code, but some bad modules may show again.

Under the 10 year 150k mile warranty, Toyota would replace the battery free with that code.

While most of us warn against the poor value of "rebuilt" batteries due to very short lifespans, that may be a low budget answer if the confirmation pattern technique fails with the current battery.

Even with a rebuilt or preferably a new oem nimh, someone would still need to run the confirmation pattern unless a receipt is good enough for the emissions testing.

 

I am a bit confused. What does P0A80 have to do with the emissions check? Is it because the emission testing rejects simply based on the fact that CEL is ON?

 

California requires no codes.

 

A Prius can't meet its emissions targets if the traction battery is to far gone.