PriusV no start - What would you do?

Looking for some input from the hive on my currently in-operative Prius

The culprit: 2012 PriusV - original battery ~160k miles

What happened:
Drove it 1/2 mile to grocery store and parked it (put in P). Left it on with ac and radio going. The smart key was in it with a driving-age passenger in the passenger seat.

I came out of the store about 10 minutes later and the radio and blower fan were still running but 'all' the dash warning lights were now on.

At this point I tried to shift to drive or reverse and it would not go into either position, just neutral.

I tried turning it all the way off and back on and it would not go to Ready mode which is necessary to select drive or reverse.

Suspecting 12v battery had drained down too low, I tried jumping with a jump box under the hood with no change.

Tried jumping it from another vehicle under the hood, no change.

Tried jumping it from jump box straight to the 12v battery in the back, no change.

Reset the 12v by pulling the ground and traction battery by pulling the big orange interlock

On the next attempted start, a bunch of messages showed up on the dash for a second and quickly went away.
At this point I gave up and waited for a tow.

Hoping that it was just a weak 12v battery causing computer problems, I had it towed to a local goodyear.

They ran some diagnostics and said that the 12v battery tested good, the interlock tested ok and it has two codes:

P0A0D - hybrid safety interlock problem detected
& 
U0110

When I look up U0110 the generic code definition is -  U0110 Data bus: drive motor control module - no communication - Some internet searches regarding this code point towards the inverter.

But, What the shop put in the notes is:   U0110 High energy battery malfunction detected

And so they quoted me a replacement battery and said 'that usually fixes the problem'.

So, I want to get a 2nd opinion and not replace the battery if a) I don't have to & b)its not actually the main problem (I'm sure it has some weak cells).

Do I take it to a dealer? Which one in the Dayton, OH area? Find a good independent hybrid specialist? Suggestions?

I'm not troubleshooting it myself but I want to have some confidence that it's been properly diagnosed.

I suspect that if you swapped in a brand new 12V battery it will magically fix itself. Toyota dealer might have to work some magic via the OBD2 port.

Do you have a battery charger?  Charge the 12v battery, directly, not through the under hood port.  

Do you have a code reader?  I have often found that with no codes showing but the car acting odd, I can use my cheap bluetooth code reader set to "clear codes."  I have had instances where these cars get "confused" and that clearing of "no real code" seems to un-confuse them.

cghstang_chris said:

Looking for some input from the hive on my currently in-operative Prius

The culprit: 2012 PriusV - original battery ~160k miles

What happened:
Drove it 1/2 mile to grocery store and parked it (put in P). Left it on with ac and radio going. The smart key was in it with a driving-age passenger in the passenger seat.

I came out of the store about 10 minutes later and the radio and blower fan were still running but 'all' the dash warning lights were now on.

I'm confused at this point.  If the car was in P and the key in it, the car was on and "ready" the whole time.  How did the car go to "unready" while sitting there?  

Is it possible, the passanger hit the power button, from the passanger seat in an attempt to turn off the car?  Becasue they tried to turn the car off w/o their foot on the parking brake, the car would go into an "accessory" style mode.  This would take the car out of the "ready" mode and would wear down the 12v battery.  

Charge the battery or replace the 12v battery.  

OR...

Car was "ready" while you were away but habitually, when you re-entered the car you hit the power button.  This would cause the car to go into an "accessory mode" and make it undrivable.  

The correction to this should be a looong hold of the power button with your foot on the brake.  Then after a very brief wait, a standard restating of the car with the normal hold of the power button w/ your foot on the brake.  

My 4 Prius are Gen2 but happy to talk...  4!9  .  54!  .  !335

Thinking further...is the little watch battery in your key fob dead?  

Touch fob to the power button

How to change battery:

I have the exact car with 86k on it and saving this for future reference.  Following with interest.....

cghstang_chris said:

I'm not troubleshooting it myself but I wan to have some confidence that it's been properly diagnosed.

I did troubleshoot it myself.   It was not properly diagnosed.

The interlock code cleared and didn't come back after properly seating the main HV battery disconnect.

The U0110 code went away after replacing a fuse. Previous owner added aftermarket HIDs and they are tapped in to the PCU fuse slot with an "Add-a-Circuit Fuse Tap". Checking this fuse is step one of troubleshooting the code per toyota instructions found online. If it had needed step two, it was going to the dealer.

I did check the 12v battery and it is original to the car with a 2012 date code. It will be replaced shortly.

The next time the car has a problem that I don't want to deal with, I now know where not to have it towed.