P3190 – Poor Engine Power P0A0F – Engine Failed to Start

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by ToyotaCoyotta, Jul 23, 2025.

  1. ToyotaCoyotta

    ToyotaCoyotta Junior Member

    Joined:
    Dec 12, 2024
    53
    9
    0
    Location:
    Lithuania
    Vehicle:
    2009 Prius
    Model:
    III
    I want to share a situation that has happened a few times over the past 4 months: while driving normally and pressing the gas pedal, suddenly the gasoline engine doesn't start—no matter how much I press the accelerator, the RPM stays at 0 (I have an additional P10 HUD sensor for that). The car runs only on the battery, and after stopping, turning off the ignition, and restarting the engine, everything works fine again.

    After performing diagnostics, two error codes were found:

    • P3190 – Poor Engine Power

    • P0A0F – Engine Failed to Start
    This situation hasn’t caused major problems, but it’s definitely inconvenient. Also, I have to go clear the error codes manually, otherwise the Check Engine light stays on and "Check Hybrid System" keeps flashing.

    could poor quality or incorrect installation of the LPG system (gas system) have caused these issues? Its just a random guess because I only had the car for like couple weeks before installing gas

    Also, before the gas system was installed, the engine oil was clear, amber-colored, with no residue. After the installation, I started noticing sludge/dirt when checking the oil level. That seemed strange to me because I use Liqui Moly oil, while a colleague who also has a Prius 3 with LPG uses the cheapest oil available, and his oil is still just as clear as mine was when I first bought the car.

    I’m attaching photos with freeze frame data for P3190 and P0A0F errors during the malfunction. Can you help me read these?
    Poor Engine Power P3190.png Engine failed to start 5.png Engine failed to start 4.png Engine failed to start 3.jpg Engine failed to satrt 2.jpg Engine Failed to start 1.jpg
     

    Attached Files:

    #1 ToyotaCoyotta, Jul 23, 2025
  2. hurricos

    hurricos Junior Member

    Joined:
    Aug 20, 2023
    31
    4
    0
    Location:
    Burlington, Vermont
    Vehicle:
    2008 Prius
    Model:
    One
    The issue is *absolutely* your LPG conversion, yes. Who did your conversion? How do they expect their system to communicate with the ECM - surely they're not just hooking the LPG injectors to the injection pulse from the engine?

    Note when these freeze-frames are being taken -- accelerator at 80%, pulling >90A, with `Calculate Load` at >90%. The engine cannot provide as much power as the system expects. Note the fuel trim closely as well - the ECM doesn't know why the amount of oxygen in the exhaust gas is so high, so it has to add a ton more fuel (open up the injection pulses) to cover for how little fuel it's getting.

    As `Calculate Load` approaches 100, the system is unable to source more power, and sets P3190 (I don't have the DTC manual close at hand to tell you exactly what determinant is used in your case). Once that occurs, sounds like in your case, the system goes into hybrid trouble state and the engine shuts off and will not restart until a new drive cycle.

    As for the sludge in your oil - same deal. Your fueling system is not running where it thinks it is, and there are side-effects.

    > while a colleague who also has a Prius 3 with LPG uses the cheapest oil available,

    Did your colleague install the LPG system the same way as you did, or does your colleague have an incentive to lie to you?
     
    #2 hurricos, Jul 23, 2025
    ToyotaCoyotta likes this.
  3. ToyotaCoyotta

    ToyotaCoyotta Junior Member

    Joined:
    Dec 12, 2024
    53
    9
    0
    Location:
    Lithuania
    Vehicle:
    2009 Prius
    Model:
    III

    my colleague has a different gas system calles aeb mars (different brand) and a different person who installed it,

    he doesnt have an incentive to lie to me, because i saw with my own eyes, he doesnt have this issue and his oil is amber color
     
    #3 ToyotaCoyotta, Jul 24, 2025
    Last edited: Jul 24, 2025
  4. ToyotaCoyotta

    ToyotaCoyotta Junior Member

    Joined:
    Dec 12, 2024
    53
    9
    0
    Location:
    Lithuania
    Vehicle:
    2009 Prius
    Model:
    III
    Where do you see accelerator at 80%? I cannot see which line you refer to
     
    #4 ToyotaCoyotta, Jul 24, 2025
  5. hurricos

    hurricos Junior Member

    Joined:
    Aug 20, 2023
    31
    4
    0
    Location:
    Burlington, Vermont
    Vehicle:
    2008 Prius
    Model:
    One
    I elided the "Accelerator Degree" line and "Motor Temp No1" lines. The actual accelerator position was 50, 51%. Anyways, you need to correct your fueling somehow.
     
    #5 hurricos, Jul 24, 2025
    ToyotaCoyotta likes this.
  6. ToyotaCoyotta

    ToyotaCoyotta Junior Member

    Joined:
    Dec 12, 2024
    53
    9
    0
    Location:
    Lithuania
    Vehicle:
    2009 Prius
    Model:
    III
    Could you please be more specify or make it a little more simple on how to explain to the LPG person why it's LPG causing this? I have a reason to believe he will try to avoid responsibility
     
    #6 ToyotaCoyotta, Jul 27, 2025 at 3:10 PM
  7. hurricos

    hurricos Junior Member

    Joined:
    Aug 20, 2023
    31
    4
    0
    Location:
    Burlington, Vermont
    Vehicle:
    2008 Prius
    Model:
    One
    The fuel trim is way off. That's your easiest tell. The LPG conversion was not done correctly; if it had been done correctly, the system would have been modified such that for the same pulse width emitted by the ECM, the quantity of oxygen consumed by that amount of fuel would be the same whether it is gasoline or LPG.

    They did not do that, and as a result your ECM is unable to compensate. I'd suggest using your TechStream on your colleague's car and confirming that their fuel trims are near +/- 10%.
     
    #7 hurricos, Jul 28, 2025 at 9:55 AM
(You must log in or sign up to post here.)