red triangle testing

The procedure you saw was for narrowing down the cause of a P0AA6 code, the code that means there is an electrical isolation fault somewhere in the car. If P0AA6 is the code you have, that procedure will help you figure out if the fault is in the battery, frame wire, inverter, transaxle, air conditioner, etc.

If P0AA6 is not the code you have, that procedure won't tell you anything useful.

P0AA6 is one of around a couple hundred possible trouble codes that can light that triangle.

So if you see the triangle come on and you just sort of guess that P0AA6 is the reason, without reading the codes, and then start working through tests that are for P0AA6, you're kind of assuming a lot.

Reading the codes first can save you some trips down rabbit holes.

 

Besides having one or more codes in one of many different electronic systems, there are also a few possible things that could trigger the "master warning light" (red triangle) without necessarily setting a code (I believe brief low engine oil pressure can do this).

So, if you have the warning light come on, then it's best to check all the underhood fluids for level and condition, then scan ALL the systems on the car with a Prius compatible scantool (such as Techstream). Many aftermarket scantool report "no codes present" when there are codes - but the scantool just can't access them.

Whatever caused one of the systems to trigger the light is unlikely to "fix itself" because you just cleared the code.

Posted via the PriusChat mobile app.

 

I guess changing the entire HV battery is one way to fix a problem with the current sensor.