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P3191 and P0A0F/204

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by black_jmyntrn, Aug 10, 2024.

  1. TMR-JWAP

    TMR-JWAP Senior Member

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    Don't over complicate things. Pull the air filter cover and filter off. Have someone do the start sequence for you while you spray starting fluid into the throttle body. See if it will actually run. At least then you'll know if its ignition related, or fuel related. Could be something as simple as no fuel. Don't over complicate it.
     
  2. black_jmyntrn

    black_jmyntrn Senior Member

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    okay sooo... turns out the fuel pump is good... i read once there is a newer ecu that has more time to allow the system to balance itself out versus throwing these codes. For the life of me I cannot find the thread with the specific ECU number... or is it a calibration id I need to apply?
     
  3. ChapmanF

    ChapmanF Senior Member

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    I seem to remember reading about that, and it was a calibration (after all, it's a pretty easy firmware fix to just wait a bit longer before giving up). Try looking on TIS or NHTSA for TSBs that mention those trouble codes.
     
  4. black_jmyntrn

    black_jmyntrn Senior Member

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    hahaha, I'm definitely not giving up... too much riding on getting this thing running.

    I did sign up for TIS and nothing was there, will check NHTSA! Thanks for the tip on NHTSA.
     
  5. ChapmanF

    ChapmanF Senior Member

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    All the TSBs are on TIS. You can also find them on NHTSA, but I don't expect anything there that's not also on TIS.
     
  6. black_jmyntrn

    black_jmyntrn Senior Member

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    kid you not.. in the two day membership, entered in the vin and all.. either I'm blind or I couldn't find it on the site.

    have you ever performed a ECU update? I've been trying to see if Techstream is all id need or is it just easier to find one with the updates already provisioned then swap it in.

    I'm also considering wiring up a switch and relay to the connectors on the fuel pump relay so I can have manual control of the fuel going to the engine to see if I can get it started that way.

    edit: I just found the below document on the NHTSA site... looks simple enough and its why I didn't find it on the actual website. It appears its through Techstream. :)

    https://static.nhtsa.gov/odi/tsbs/2019/MC-10164330-9999.pdf
     
    #26 black_jmyntrn, Sep 5, 2024
    Last edited: Sep 5, 2024
  7. mr_guy_mann

    mr_guy_mann Senior Member

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    I would doubt that this is a "calibration fault". I looked at the freezeframe data from post #1 - it suggests that the engine wasn't really running at all.

    The A/F and O2 sensors read as "complete fuel cut" lean (ie, those are the readings you might see when the ECM turns off the injectors during high speed decel)

    The 4th page shows that the ecu expected around (+) 75 Nm torque from the ICE, but it used (-) 12 Nm (ie, the motor was spinning the ICE, not the other way around.

    If you are sure that the fuel pump operates and it has usable gas in the tank, then I'd look at whether the injectors actually open and spray.

    Posted via the PriusChat mobile app.
     
  8. black_jmyntrn

    black_jmyntrn Senior Member

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    ohhhh... soo.. small update... I started from the beginning by checking power to the pump, when I removed the connector from the tank, I noticed the #3 pin was bend and basically not going into the connector. I applied power to test it and it didn't work.

    so I went and bought another used gas tank and before installing it, went to test it. When the 14v from a Prius Prime 12v battery when it was on didn't work after sometime I ended up trying it with a 12v putting out 12.33V. the next thing you know she was squirting with a nice stream. I proceeded to test the tank still in stalled and you know what... it was working!

    Thats why now I was thinking its the ECU needing to have the latest calibration update installed. This time, versus me hearing what sounds like the RPM gradually increasing before the red triangle of death and the care pops out of ready mode... the car had a more steady or normal room sound yet it still threw red triangle only this time Ready was still active.

    https://black.jmyntrn.com/wp-content/uploads/2024/09/2009_Prius_1NZ-FXE_JTDKB20U293466431_9-4-2024-63330-AM.csv

    that's the file from my techstream as of yesterday.
     
  9. ChapmanF

    ChapmanF Senior Member

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    Well, I do vaguely remember seeing a TSB that did refer to P3191 under difficult starting conditions (like very cold weather), and there was a calibration update listed, and IIRC all that was changed in the firmware was a few more seconds were added to the timeout for the cranking attempt. I don't remember the TSB number offhand, sorry to say, nor do I remember for sure if it was for gen 2 or another generation.

    But anyway, that seems like a fix for a problem where the engine usually starts, or almost starts in hard conditions, and just needs a few more seconds' grace. But your Techstream captures keep looking like there aren't any signs of life, like the engine is still being cranked (−21 Nm torque) after 13 seconds (think about starting an engine, and count off 13 s on a stopwatch—that's a long time to crank). And I'm not guessing September in LA really counts as "difficult starting conditions".

    This doesn't seem to me like the kind of borderline situation where allowing a few more seconds to crank would make it all better. Rather (as a US Robotics modem support guy said to me on the phone once): "sounds broke."

    The fuel pump is supposedly running, and the injectors are supposedly being pulsed at 8.96 ms, but the short fuel trim is at +20.3% and the bangity-bangs are not happening.
     
  10. black_jmyntrn

    black_jmyntrn Senior Member

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    okay hold on... sounds like you are saying the motor I have in there is bad... the jdm motor that I just installed.... hahahahahahaha you know, I tell people the last few years I've been doing this prius stuff... its like someone has a voodoo doll of me and they are a powerful force. I just wonder if the doll is bald like me or if it has hair.... woooo sahhhh...

    so no bangs, leads me to think I should put new spark plugs in! Ive just wanted to get it started and running then I planned on swapping in new plugs, injectors and the rest of the sensors. What should the short fuel trim be at?
     
  11. mr_guy_mann

    mr_guy_mann Senior Member

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    If the engine is running "perfectly", then the upstream A/F sensor reads (around) 3.3V, the downstream O2 reads around 0.6-0.8V (with a healthy - lit off - cat), and short + long fuel trims near 0%.

    The freezeframe data still shows "no" fuel getting into the engine. (crazy lean). How about them injectors? Maybe get a fuel pressure gauge installed and see what the pump can produce.

    Do you have another Gen2 Prius handy? Easiest way to figure out what's wrong on your broken car is to compare it with "a known good example" from a working car.

    Posted via the PriusChat mobile app.
     
    #31 mr_guy_mann, Sep 5, 2024
    Last edited: Sep 5, 2024
  12. black_jmyntrn

    black_jmyntrn Senior Member

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    ahhhhhh, I see said the blind man! I'm putting focus on fuel and will get a pressure tester and more than likely some new injectors then head back to the car here shortly.
     
  13. black_jmyntrn

    black_jmyntrn Senior Member

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  14. MAX2

    MAX2 Member

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    Weather conditions can affect, but it must be a combination of problems.
    One cold autumn, I used a hack for the false mode S4, apparently filled up with not very good fuel and the ECU, receiving incorrect values from the temperature sensor and the Mass Air Flow Sensor, turned off the engine, shaking the whole car.
    The check engine light came on.
    Here, according to the value of the long fuel correction, there is also a clear cutoff for fuel supply, which indicates that the system considers the fuel to be excessive.
    Lack of oxygen is a problem with the throttle valve, the Mass Air Flow Sensor, or an incorrect oxygen sensor behind the engine.
     
  15. black_jmyntrn

    black_jmyntrn Senior Member

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    well I did replace the throttle body with one from auto dismantlers and cleaned it out. The resistance on the MAF and TB two electric parts all checked out... but oxygen sensor behind the engine? you mean the one on the cat that you changed from inside the cabin? if sooo... that's one I haven't checked, it came with the catalytic converter that was installed...
     
  16. MAX2

    MAX2 Member

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    Oxygen sensors provide feedback.
    If all systems and the ECU are working properly, the sensor monitors the exhaust after the engine.
    If the sensor thinks there is a lot of oxygen, it tells the ECU to add gasoline.
     
  17. ChapmanF

    ChapmanF Senior Member

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    Using a mechanics' stethoscope, are these injectors even clicking during the crank attempt?
     
  18. mr_guy_mann

    mr_guy_mann Senior Member

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    Not quite. Long term fuel trim is a learned correction. This engine hasn't run at all, so it has not had enough operational time to see that short term trim is bad. The default value is 0%.

    The upstream Air Fuel sensor could be bad (reporting a false lean condition), but I wouldn't expect that to cause a "no start". Poor running with black smoke out the tailpipe, sure. But not this. (I would ignore the downstream O2 until the engine is warmed up to normal operating temperature.)


    Posted via the PriusChat mobile app.
     
  19. black_jmyntrn

    black_jmyntrn Senior Member

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  20. black_jmyntrn

    black_jmyntrn Senior Member

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    So, it turns out that a full bottle of Marvel Mystery Oil may have been added to the gas tank some time ago. I powered the fuel pump and drained the fuel through the front of the car. Afterward, when I tried starting the car, the dash displayed "Fuel Tank Empty." I added new fuel, which was weeks ago.

    During the engine installation, the fuel line in the engine bay was accidentally damaged from excess pressure while removing or setting the engine. After several failed attempts to repair it, I found a replacement fuel injector hose at a VW garage (since they use metric). I secured it with two twist clamps on each end and proceeded to attempt starting the engine.

    When I pulled the injectors, the fuel didn’t have a strong gasoline smell, and there was some oil residue but not much. I powered the fuel pump to let some fuel flow. Notably, when I removed the injectors, I heard a good pressure release. I started suspecting that maybe the fuel had gone bad, even though it was recently added after installing the tank. I added half a can of Seafoam, an octane booster (7 points), and some fresh gas into the throttle body and tank.

    When I tried starting it again, the car sputtered a lot more, especially when I put it in reverse. I even saw a bit of white smoke from the exhaust. But once again, after a few seconds, the red triangle came on, and the car shut off. It sounded like the RPMs were gradually increasing just before it shut down.

    Here’s another thing: when the fuel dries, it crystalizes. After this last attempt, I noticed fuel crystalizing near the repaired section of the fuel line where I hadn't secured it with a second clamp (since I didn’t have a heat gun to properly fit the hose over the pipe). Thinking this was the issue, I drove home (~27 minutes) to grab my heat gun, came back, and properly secured the clamps. I added more gas to the throttle body, but the same error codes appeared.

    Even if I get a fuel pressure tester and the pressure is off, I’m starting to think I might need to replace that metal fuel line entirely to restore everything to OE spec without relying on my temporary fix.

    This is how the repaired line looks now..
    https://black.jmyntrn.com/2024/09/09/fixing-the-gas-line-in-my-2009-prius/?utm_source=priuschat&utm_medium=BJpaste&utm_campaign=commentlinkSeptember2024


    after uploading the logs to AI... this was its suggestion.


    Based on the logs and information you provided:

    Key Observations:
    1. Fuel Pump Status:
      • The logs show that the fuel pump status is recorded as “OFF” in some instances. Ensure the fuel pump is being activated correctly during the start-up process. If it’s not turning on when it should, it could be due to a fault in the fuel pump relay or wiring.
    2. Throttle Position Sensor (TPS):
      • The readings for the TPS from the logs might indicate inconsistent values, especially when comparing them to expected ranges. This could suggest that the throttle body or sensor is not functioning correctly, affecting engine start-up and performance.
    3. Error Codes:
      • P3191 (Engine Does Not Start): Indicates issues with starting the engine. This can be due to fuel delivery problems, throttle issues, or other related components.
      • P3190 (Poor Engine Power): Suggests that the engine is not generating the expected power, which could be linked to fuel delivery or air intake issues.
    4. Voltage Readings:
      • The voltage readings from the logs suggest that the battery and charging system are providing adequate power, but you noted fluctuations. Ensure that the voltage levels are stable and within the expected range for proper engine operation.
    Next Steps:
    1. Verify Fuel Pump Operation:
      • Double-check the fuel pump activation by testing it with a known good power source. Ensure it turns on and operates as expected.
    2. Inspect Throttle Body and TPS:
      • Recheck the throttle body and TPS for proper operation. Ensure that they are clean and that the sensor readings are within the specified range.
    3. Clear and Monitor Codes:
      • After making adjustments or repairs, clear the DTCs and monitor if the error codes return. Track any changes in engine behavior and DTC appearances.
    4. Additional Testing:
      • Test the fuel injectors and verify fuel pressure to ensure that the fuel system is delivering the correct amount of fuel to the engine.
    The logs provide a snapshot of the vehicle's status and highlight areas where further investigation is needed. Addressing these specific components should help in resolving the engine start and performance issues. Let me know if you need further details or assistance.
     
    #40 black_jmyntrn, Sep 9, 2024
    Last edited: Sep 9, 2024