Prius fails to start, P0A0f, P3193

I actually have 2 gen 2 Prii that appear to be showing the same symptoms and codes, P0A0F and P3193. Confirmed earlier that it wasn’t out of gas, just reporting this code when the engine didn’t start after cranking. I’d like to diagnose the problem rather than throw parts at it, but I’m not really sure where to start. Is there a troubleshooting flowchart or guide in the right direction?

 

Thanks for the response. I have a grid charger, so I’m keeping the traction battery charged up every night. I bought a can of maf sensor cleaner and I’ll start with that. I have dr Prius, torque app, and a pretty good bii-directional code reader, so I can get live data and freeze frame info. Nothing appears out of place, but I might not really know what to look for. Any advice would be appreciated.

 

Thanks all for the responses.
1. I bought the grid charger from the company that reconditioned the batteries, and am following their instructions for charge rate (300 ma) and final voltage (225 VDC). The battery had dropped to 184 VDC and wouldn’t turn over the engine before I charged it.

2. Both cars show empty fuel gauge, but have been filled to overflow with a gas can. I’ve been convinced that this condition will be resolved when I get the engines to stay running.

3. Prius #1 is indeed the one referenced in my previous posts, and I have repaired the cluster with a new capacitor, but it still won’t start, although the cluster now works. Maybe I should have posted to the same thread, but I’m now focusing on Prius #2, which was running well until recently.

I bought a can of CRC maf cleaner and CRC throttle body cleaner and I’ll try that next. I will post results to this thread.
I watched the PHAD video when it was first posted to YouTube, but I’ll watch it again to see what info I can gain.

 

I have two cars. #2 Prius, the one I’m focusing on now, has been running for almost 3 years, no one has touched it besides me since the day I bought it. I replaced both batteries and the inverter coolant pump when I bought it, and it’s been running since then. Maf and throttle body clean didn’t help any, so I think I’ll change the spark plugs next. Wish there was a better way to systematically diagnose the issues. My son’s celica gives me cylinder misfire codes if I have ignition issues, guess I was hoping for something like that to direct my efforts.

 

Thanks for the responses. I guess I’ve gotten accustomed to the odbii diagnostic codes typically provided by modern cars. For example, my son’s 2002 celica tells me “misfire cylinder #3” , or “crankshaft/camshaft correlation fault”, but instead the Prius tells me “engine failed to start”, or worse yet “ out of fuel” when it really isn’t. So I guess I need to go back to the old school diagnostic processes like we used back in the day to figure this out. Fortunately, I have a lot more resources available to me today than when I was working on my first car, a 1965 Triumph Spitfire, back in the late 1970’s. I have a pico-scope with pressure transducers, fuel pressure meter, compression tester, etc. and an AutoZone 6 blocks away that will rent most anything else that I might need. I’ve even still got a timing light, if I can figure out something to use it on. I’ll try to start with the most likely failure points, I’ll pull the plugs and check for spark, test fuel pressure and compression if I get that far.
A few answers to mr_mann_guy questions:
Yes, engine spins, haven’t yet pulled plugs and checked compression, maf sensor reads a reasonable value, I’ll check and record again today. Haven’t yet checked fuel pressure, spark plugs firing, or injector pulses, I’ll crank up the pico scope today, if I get that far.

Any additional advice would be awesome.

 

Prius #2 is running again!!! I did three things to finally get it going:
1. Replaced the 12 V battery. Old battery read 4.8 V even after charge.
2. Replaced spark plugs. Old plus were Denzo iridium and had a very wide gap compared to the new NGK’s
3. Filled it up with gas. Daughter said the gauge wasn’t reading right, but she knew it was full. I decided to assume nothing, and start from ground zero. I put in about a gallon of lawn mower gas, then put in a full 5 gallon can. This got it up to half on the gauge, so I drove it to a convenience store and put in 4.2 gallons more. Yep, it was definitely out.

Red triangle blinked on once, then didn’t see it again. I’m going to drive it a bit before returning it..

 

Prius #2 seems to be running fine, but the red triangle flashes up very briefly every half hour or so without setting any codes. I don’t feel confident to give it back to my daughter if this is happening. Anyone know what could be causing this? Is it a traction battery on the way out? Should I run the Dr Prius battery health test to figure it out? Should I just ignore it until gets bad enough to set a code?

 

Haven’t tried that yet, I’ll try it when I get home this weekend.

 

Thanks for your thoughtful reply. Low oil level is a distinct possibility. The car uses some oil, and my daughter recently slid on ice into another car, resulting in the hood being unable to be opened. I fixed that (kinda), and now can open the hood, but I didn’t check it when I had the chance. I’ll untie the rope holding the hood down and check it tomorrow.