HELP! P0A7A HYBRID/BATTERY PROBLEMS. Suggestions?

P0A7A and P0A92 might point to a transaxle failure. Both of those diagnostic trouble codes should be accompanied by a three digit subcode which might help to narrow down the issue further.

 

You will need Mini VCI to obtain the three -digit subcodes. If you obtain those then maybe you can get a better idea whether the root cause is the inverter or the transaxle.

 

I realize this is an old thread, but hopefully you can assist. I have a 2005 Prius with 212 miles which basically was stored in my garage for 2 years with batteries disconnected. Upon my return I reconditioned the HV battery and got it running for about 5 miles and got fresh gas before it went into limp mode right back into my garage. I have added a new 12V battery and I am now down to 3 error codes P0AA1, P0AA4 and P0A7A.
I have found one suspect corroded connector above the 12V battery but no others yet. With these codes, besides checking relays and connections, should I be checking the HV Control ECU? and if so, how would I do that?
Also, on one attempt to start I heard a pop sound come from the engine compartment. On my latest attempt, I got the ready light for a moment until the ICE attempted to start and abruptly stopped with a clunk sound and all the warning lights reappeared.
Any suggestions or wisdom you can share is greatly appreciated.

 

In your situation it would be extremely useful to have a scantool (such as a copy of Toyota's Techstream with a mini VCI cable- amazon or ebay- installed on an old windows laptop) that is capable of reading the 3 digit INF or subcode that goes with each of the dtc's you've listed. Then you could look up the specific diagnostic info for that specific fault in your copy of the service manual.

There are two subcodes for P0AA1 (positive contactor stuck closed), just one for P0AA4 (negative contactor stuck closed), but 14 for P0A7A (inverter generator performance).

Posted via the PriusChat mobile app.

 

Yes, Thank you- that's a lot of checking to do so I've been focusing on trying to get my Techstream re-connected so I can narrow it down, but of course I'm running into error messages there too. Either way, it looks like I'll be busy for a while. I basically started over with trying to download V12.00.127 several times and either didn't crack or I ran into error messages. Tried a couple newer version downloads and ran into different error messages. I'm ready to start over again with V12.00.127 as it may be easier. The directions I am following are rather vague. I am working with Windows 7- 32 bit and Was trying to upload my drivers for my VCX NANO SAE J2534, have not been able to get either set of downloads to run right.

 

Try this link to run techstream in a VM on your Win 7 system. The .ova file (the virtual machine) already has techstream installed, configured, and licensed. Very easy setup. Works on Win10 also. Easiest way to get up and running and doesn't affect anything on your Win 7 OS. And it's free.

5 min to Download + Install Techstream V12 VMware for VXDIAG Toyota | OBDII365.com Official Blog

 

That all sounds too good to be true after two days of struggle. And as I make this current attempt- problems arise. I downloaded and opened the Virtual machine- good- but have no idea how the techstream download will go inside of it? I Started the techstream download- and it stopped and I got error message on memory shortage- with two options came up? I downloaded Mega sync Setup64 but stopped there. The other option was a download option/version -called the desktop app? I had chosen the standard download. I am obviously no computer wiz, but trying to muddle my way thru this. Any guidance is very welcome.

 

Open VirtualBox, click File menu dropdown and import appliance. Find where you put the .ova file and select it. It will install the image and you will be ready to run the VM. Takes about 1 minute.

Once the .ova is installed just click on start and the VM will fire up into Windows XP and just run the Techstream icon on the desktop. Be sure to make it full screen for easy visibility. Now you will have a complete Windows XP with Techstream running in a sandboxed environment.

This VM is completely isolated from your main Windows OS, so no worries about malware issues or crosstalk between the OS. I find this is the easiest solution to get Techstream running on a modern laptop without having to resort to sourcing an old laptop and being able to use your everyday laptop for this purpose without having to worry about specific driver nightmares or having to turn your antivirus off because there are certain files tagged as a virus with a modern OS (the keygen program).

You can also turn on copy from the VM to the Host OS to copy from the VM to your normal OS if you create reports you want to view on your Windows 7 OS.

Let me know if this works as well for you as it does for me.

 

Again, that sounds good- but my progress stopped dead when I got the error message of memory shortage during the .ova download. Unsure how best to deal with that.

 

I don't think you really mean download do you? I just tried the supplied link to the ova download from the linked website and it is working fine. I re-downloaded the ova file to make sure. More likely you mean during import of the ova. Does that sound more correct?

 

Not sure about that- I attempted the "standard download" from MEGA to my laptop a couple times- it slowly was downloading before reaching the halfway point after 30 minutes and stopped- with an error message of memory space shortage. I have plenty of memory to handle this and should not download so slow. Not sure what's going on there. I will continue other attempts.

 

Any updates worth sharing?