Red Triangle of Death on 2004 Gen II, 240k, 3 codes

Hi all!

So I've read a bunch of these similar threads and I think I've got something different enough to warrent a new thread.

Problem started on 2/13; changed the oil in the AM and drove it around for the rest of the day - levels were fine and no drips noticed and the dipstick shows everything is kosher. Didn't drive it on V-Day at all. Started it up on Wed and boom - Red Triangle of Death, Check Engine, ((!)), and VSC lights all come on. Had to take kid to the doctor, so we drove to the office with the lights on. Halfway there, the VSC and ((!)) lights went off. Drove it sparingly the rest of the week; sometimes all four lights were on, other times just the RToD and Check engine lights stayed on. I checked the 12V battery through the diagnostic screen after I let it sit overnight and I was sitting at 11.9 V at on, 11.7 at ACC (no lights, A/C, or radio), and 13.9 at Ready. From what others have posted, that seems to be about right. Also noticed that the battery level indicator for the traction battery seemed like it would rapidly fluctuate between maxed out and two purple bars and would visibly drop while sitting still in Ready mode. What's more the battery level would show a complete charge after only a few seconds of braking. Regen brakes seemed off as well - almost like they'd clamp down hard immediately after toucing the pedal and then release to a more normal feeling stop. Today, it seemed like the ICE is constantly cycling on and off while the car is sitting still (makes me think it can't figure out whether the battery needs charging or not).

Anyway, finally got the chance to get at code reader on it today and this is what it said:
C1310 - malfunction in HV system
P0A1F - battery energy control module
P0A80 - replace hybrid battery pack

So, what I'm wondering is whether the hybrid battery has actually given up the ghost or is the P0A1F code indicating that something has gone bad with the battery ECM and in turn causing the P0A80 code as well as the other issues.

I turn to you Internet of Things to help me solve this puzzle!

-Servo

 

12V is 4-5 years old. Can't remember exactly when I replaced it.

 

JC,
Any chance it's a bad cell or is it going to be the whole battery pack?

 

Great, thanks for the info.

Is this thing drivable or should I park it until I can get somebody to look at it? I'm not going to damage the inverter or anything while the battery is slowly dying am I?