P3190 P0A0F C1259 Check Hybrid System on 2010 Prius II

My 2010 Prius with 97k miles got the "Check Hybrid System" error yesterday (Oct 17), and the engine would not start. Unfortunately for me it came on just after I had left my house and started going uphill. I made it up to the end of the block, circled around, and parked by the side of the road (all on just the battery). I then tried turning the engine on and off 3 or 4 times (oops).

I got the car towed to the nearby Toyota dealership for a diagnostic and it came back with P3190 P0A0F C1259. Here's what the dealership wrote: VEHICLE STARTED THEN DIED. CHECKED CODES, FOUND P3190 P0A0F C1259. FOUND T-SB-0041-15 MAY APPLY. INSPECTED PURGE VSV AND HOSE, TSB DOES NOT APPLY. MORE TIME FOR TEAR DOWN OF MULTIPLE PARTS IS NEEDED FOR PRELIMINARY DIAG STEPS.

Here are some other details in case they're helpful:

• Did an 800 mile drive last Thursday (Oct 12)
• Used the car the past week with no issue
  
• No issues with mpg, getting about 43-45mpg
• Never noticed any issues with the HV battery charging or discharging too quickly
• Never noticed any oil leaking
  
• Dealer says the 12V battery is fine
• The car is parked outside, and I'm in Seattle where it rains a lot, but it's been parked outside with no issues before

This failure happened very suddenly. The only thing I had done that was different when I parked the car the night before was to put a windshield cover that wrapped around the side mirrors to prevent leaves from falling onto the windshield. I doubt that's relevant though.

I've spent some time reading this site for potential causes of this issue – things like debris in the mass airflow sensor, fuel pump issues, dirty throttle body, oil in the intake manifold, EGR valve, PCV valve, burst fuses. It's a lot, and I wanted to ask for help here to figure out what I should do next.

The dealer wants to "inspect engine for possible head gasket leak," "inspect hv battery for corrosion," and "inspect and clean hybrid cooling fan motor." (And charge me $1300 for that.)

Concretely, here are some questions:

• I was under the impression that the dealer would have used techstream and given me some information from it as part of the diagnostic, in order to narrow down what might be the issue. As it is, the dealer has only given me information that I could have gotten with a Dr. Prius compatible obd2 sensor. Is it reasonable for me to ask the dealer for more details?
• The P0A0F should have come with an INF code, right? (I didn't get it from the dealer.)
  
• Techstream should indicate the SOC of the HV battery, right? Based on what I've said, do you think the charge is too low to start the engine, and will I need to have the dealer charge the HV battery?
• What should I do next? I'm no car expert, but I do have an automotive wrench set and a multimeter. I ordered some MAF cleaner and I'm going to clean that out myself. What else should I try?

I'm in Seattle, so if you know anyone who's good at working on diagnosing and fixing this issue around here, please let me know.

Thanks so much for reading.

 

Hey @the_hybrid_guy thanks! Unfortunately I don't have a grid charger. What are you thinking?