Also, If you haven't changed your tranny fluid yet, I would do that as well. It is a longshot that the tranny fluid has become slightly conductive (very slim chance). As a good measure, changing the transaxle fluid will def not hurt anything. If this were my car and, I was in your shoes, I would start with changing the tranny fluid (because its so easy). Then if I still had the problem, I would open up the battery pack and look for corrosion. Just so you know, I have been on PriusChat for about 2.5 years now and I've never seen the P3009 resolved by cleaning the battery or changing the tranny fluid but, that doesn't mean you won't be the first. The car can run for an indefinite amount of time with a p3009 fault (and judging by you mpg, yours is running fine).
I changed the tranny fluid 4 months ago, cleaned the pan and checked the level a few days ago. Changed system coolant, oil, plugs, everything other than inverter coolant 4 months ago, but level is good and pump is working. Whatever it is, it threw the triangle again last night. So I'll take a look at the bus bars soon. What are the glove requirements for disconnecting the main? Thanks for all ideas.
As of today, the warning has cleared itself and the car has been running as normal. Now I'm double stumped?
Don't get too excited, as a high voltage ground fault may come and go depending upon its severity. It'll get worse as time passes.
