2005 Prius trouble codes P0A08 and P0A09

you clear the codes, and they keep coming back?

 

What is the evidence that the car is charging just fine? I am referring to the 12V battery being charged, not the high voltage traction battery.

My guess is that, besides having a failed high voltage battery, this car also had a bad 12V battery and suffered from a botched jumpstart where the battery polarity was reversed. Hence the 100A DC/DC fusible link blew. Further, the DC/DC converter within the inverter was damaged. Am I on the right track?

If I am, and you have replaced the inverter and the fusible link within the main relay/fuse box next to the inverter, then measure voltage across the 12V battery when the Prius is READY. The voltage should be around 13.8VDC. If it is much lower, then either the replacement inverter is not working, you failed to replace the 100A DC/DC fusible link, or you have other wiring harness damage.

 

Did you get any resolution to this?

I'm having exactly the same problems with my 2nd gen Prius here. I'd love to hear if there was some solution. Thanks!

 

I have a 2008 Prius, same problem. P0A09-591 after resetting codes with TechStream and Dr Prius with car off, once engine is started then it also registers P0A08-264 as well. Just replaced inverter with a known good one, 12V battery is good, all fuses good, replaced fusible link at 12v battery. Battery is 12.5V with car off, 13.9V in ready, checked everything I can think of. Anyone have any thoughts? No other codes than these ones. Car still works fine, just want that code and red triangle gone. Any help would be really appreciated. Thanks

 

have you researched the codes in the service manual?

 

So I solved my own problem after posting this earlier this evening... when I bought this car almost 2 months ago I found an old mouse nest on the right rear wheel well near the battery cooling fan. I removed it then, never thought any more about it. After many hours of searching why I had the red triangle ,which included replacing the inverter and inverter pump, testing all fuses, plus many more testing hours, I noticed the black protective sleeving over the wires in the area where that nest was was a little wrinkled. I cut that black protective sleeve back and found a wire that a mouse had chewed and it all turned green and rotted off. I replaced that 2” section of wire and the red triangle is gone. Codes P0A08, P0A09 are also gone which I tried resetting many times in the past unsuccessfully. See pictures below. It’s the white wire in that group of wires. That was a tough one but problem solved.

 

I just wonder how a mouse got in your car, I assume that is where the wire was, inside. Not sure where the outside air comes in when your ac is set to vent, but I have a silverado and a mouse got in there and died, stupid GM did not put a screen over the the hole so I had to.

 

Remove connector and joint wires as per color code ... please note cut and joint one wire at a time.

 

What is the significance of that connector having that green corrosion on those pins? And the solution? mine has similar but less severe corrosion.

 

The presence of corrosion of those pins is indicative of a leak originating from the rear of the roof channel. (There are many threads that cover this problem.) You should check under the 12 V battery for standing water too and deal with that. If the plug fails from the corrosion the hybrid vehicle battery cooling fan, which is below it, will stop working and you will get hybrid system errors. You should deal with the leak and rehab the plug and connector if possible.