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Prius thought I had run out of gas, gave error codes P0A0F and P3191

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Egg Crate, Apr 1, 2014.

  1. Egg Crate

    Egg Crate Junior Member

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    Vehicle:
    2006 Prius
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    This morning, I started my 2006 Prius with 143k, and it had the following issues:

    1. all the warning lights came on the dash
    2. the gasoline engine sounded like it was running a bit rough
    3. when I tried to take the car to the dealer, I couldn’t go above 30 mph, and
    4. it died shortly after being on the road.

    I had it towed to the dealer, and they said the Toyota Techstream made it look like I had run the car out of gas (which I didn’t do), and they called me to verify that I didn’t run the car out of gas. They reset all the codes, and after that, the car ran fine. However, since they didn’t do anything expect reseat the codes, so I’m suspicious that there’s still some underlying issues. They gave me the printout of the codes, and they are

    1. P0A0F (Engine Failed To Start)
    2. P3191 (Engine System Malfunction)
    3. C2131 (Unrelated code about a bad tire pressure monitor)
    4. B1421 (Innocuous Sun photo-sensor error)
    5. C2318 (Low Voltage Error. I assumed this was related to the gasoline engine not running)
    6. B1271 (Combination Meter ECU Communication Stop)

    And here are a few other things that I had done to the car right before it had these issues this morning:

    1. My area had a lot of rain over the weekend and I drove it during a heavy downpour, so maybe water got in the fuel line?
    2. I had just filled the gas tank the day before. The gas station was .2 miles (if that) from my apartment, and I didn’t drive it after that, so I don’t know if I got a bad tank of gas.
    3. I had open the air filer cover (the black box over the gasoline engine) for the first time the day before (I’m trying to be more of a DYI Prius owner). I pretty sure I didn’t touch the MAF sensor, so I don’t see how think would have caused this problem
    4. The oil was changed 3k miles ago and the oil levels are fine, so there should be no issue with that.

    So that's my situation. If you all have any ideas about things to check or possible culprits, that would be great. Thanks.

    Related question: To fully reset the Prius computer, can only the dealer due that with their Techstream technology, or can I do that with a OBD II scanner or by unpluggin the 12V and the PCM/ECM/ECU for 10 minutes?
     
  2. JC91006

    JC91006 Senior Member

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    Can you check if there is water by the battery compartment and spare tire? I've read many people with a water problem getting into the car, where the 12v battery and spare tire location is at. I don't know what damage this water can cause but it can't be good if water collects there after rainfall. It's pretty tight back in the 12v battery section, but if there is water there, you should be able to see if by shining a flashlight in the 12v battery housing area.

    I'm also wondering with the rain if water could have gotten inside where the spark plugs are and gave you problems......
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Remove and check the iridium spark plugs and spark igniters. Replace the plugs now if they had not been previously changed. Inspect the plastic igniter body for rust stains, burn marks, or cracking and replace if needed. Inspect the igniter wiring harness connectors for corrosion and clean as needed.

    2. Clean the throttle body interior and throttle plate using throttle body cleaner applied to a clean cloth, to scrub those parts. Remove the air cleaner housing for access.

    3. Remove the mass air flow sensor and clean using MAF sensor cleaner spray.
     
  4. Easy Rider

    Easy Rider Active Member

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    And how old is the 12 V battery ??
    That, or it's connections, could be the problem too.
    Corroded electrical connections get even worse when wet.

    The "low voltage" trouble code might actually be significant.
     
  5. Egg Crate

    Egg Crate Junior Member

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    I'll check out the spark plugs, throttle body, and MAF sensor. I just replaced the 12V in October, so this battery should be go unless it's defective.
     
  6. Easy Rider

    Easy Rider Active Member

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    Sometimes a battery voltage problem is due to the battery CONNECTIONS and not the battery itself.
    I'm not saying it is likely that IS the problem for you but it is something that needs to be considered among the list of things to check.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I agree that the battery cable tightness should be examined, especially the negative cable where it bolts to the body and that it would not hurt to measure battery voltage. However I doubt a loose cable or marginal 12V battery by itself would cause all of the DTC noted by the OP.
     
  8. PapaWill

    PapaWill Member

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    I have the P3191 on my '07 Prius. I see that the fuel indicator is blinking so I will try to put a couple of gallons of fuel and see what happens. Thank YOU Patrick.
     
  9. PapaWill

    PapaWill Member

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    I put 2 gallons of fuel in tank and low and behold tyhe gauge registers one tick more than half full. I have done all the basics: cleaned mass air flow , changed PCV, changed spark plugs, changed oil. Both batteries are charged up. Connected the car to techstream and still showed the code P3191. Did active test. It showed one O2 sensor to have a resistance of 21,000 ohms. Not sure what this means.

    I unplugged the fuel line, installed a plastic hose to a tank and asked techstream to run the fuel pump. Nothing. Is that definitive? Do I need a new fuel tank and pump? Or should I remove back seat and get into the fuel pump and disconnect the powepump r from said and feed 12V to it to see if it, indeed, is the pump? Or what?

    Any suggestions are appreciated!
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, you should remove the rear seat cushion, open the access plate, and either measure the voltage at the fuel pump wiring harness connector to see if it has 12VDC; or else apply 12VDC to the fuel pump socket and see what happens. Or you could measure resistance across the fuel pump socket and see what you get.

    Try not to cause a spark close to that fuel vapor source.
     
    SFO likes this.