P0AA6 wit only 526 sub code

I know there are other posts, and I reported my 2 cents on a similar post, but I wanted to post a new today find.

I had the same p0aa6 with only a 526 sub code, no 600 codes. I used the megohmeter on all the HV components, following Toyotas diagnostic checklist, and could not find the smoking gun. Lucky for me, we have 3 gen2’s. My gut told me that it was the ecu, so. My last ditch effort was to swap out the HV battery ECU from our other Prius. The swap fixed my issue. I was going to order one off eBay, but…….

I removed the circuit board from its case. My inspection of the circuit board revealed green corroded pins (orange) in and through the connector, nasty. Everything else looked ok. This connector has the wires that register the voltage from the individual batteries in the hybrid pack. First I scraped and used q tips and alcohol to clean the brass pins, but it did not do a very good job. I put it back in the car and it threw the same code several times.

At this point I thought, if I am going to replace it, why not try and give that connector a soak in vinegar and salt solution. So I did, for 2 hours. I found an old Tupperware (small, same size round as the connector) container and filled it with the vinegar salt soliton and soaked that connector. Then I made a water and baking soda solution and soaked the connector for two hours again. The pins were golden and the entire connector looked like NEW. I rinsed the connector with water and put a fan on it over night to dry. This morning I put the ecu back in the car. I just finished driving 250 miles with no code.

The weird thing I can not figure out is why this connector, out of the three connectors on the board was it corroded and green. The pins are so close and I am assuming that corrosion was the voltage leak. And ironically, the ecu I used to swap from our other car was also corroded, but not near as bad as this car.

 

Oh well. Depression sets in. The code popped back up. But the funny part. It’s original computer would never give the 613 code. The computer swap with our other Prius unfortunately gave me the 613. I have a 2008 trans, I heard the temp connectors are different. Can I pop out the 2005 connectors from the original trans and swap them to the 2008 trans? Watched the YouTube video of them dissembling the trans and they’re connected to a connector behind the connectors. Anyone have insight for the connector swaps? Is it that simple, or do I need to cut and solder the 2008 wiring temp harness?

 

By the way. A cheap code reset reader can reset the Prius from a p0aa6 situation. The code reader will say there are no codes. But if you click on clear codes, it resets the system and you can drive. I have to SUBMIT the clear the codes button TWICE.