DTC P0AA6 appears during heavy rain

I have a 2012 PriusC woth 133000 miles on it. Car is still driving goodg was until last month or so, when the hybrid system warning light appeared on my dashboard, I immediately took it to a toyota service center, they charge me a lot money to diagnose the issue, only to tell me there was nothing wrong with the car, they cleared the codes and test drive it and gave it back to me, I thought everything was resolved.

A few days ago the warning light came back on, this time I bought my own diagnostic odb2, to try to get to the bottom of the problem, this is when I was the dtc code P0AA6, i have watch multiple videos explaining this code, unfortunately my scanner did not give me a detailed code to narrow down the issue, I'm planning to take it back to toyota service center to have it check again, but before I get hassled out of my money, I wanted to ask ideas from anyone.

I did notice something common to the 2 instances the hybrid warning light came on, It was happened when I was driving thru heavy rain. I'm thinking of something gotten wet causing a short. Would you guys have an idea what it could be., thanks