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P0300 and P3191 Error Codes - Fuel Pressure Problem

Discussion in 'Generation 1 Prius Discussion' started by gerrypez, Dec 20, 2009.

  1. gerrypez

    gerrypez Junior Member

    Joined:
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    Location:
    Davis, CA
    Vehicle:
    2017 Prius Prime
    Model:
    N/A
    I have a 2002 with 165K miles. It's been flawless, until this week when I started getting P0300 and P3191 errors, starting on a cold morning. I thought I would report on it, in case others have the same issues. It seems to be common with Gen 1 cars.

    I first brought it to the dealer, and paid $110 to get the error codes.

    P0300 - means all cylinders are not firing properly. It it was P0301, it would be the first cylinder, etc. P0300 is general.
    P3191 - means the engine did not start in time

    The Dealer said it was the fuel pump, and because the fuel tank and pump are integrated in the Prius, the repair is complex, it would be $1017 to repair. I had the technician measure the fuel pressure to make sure it was low. The technician told me that Toyota is well aware of this issue. They sent out TSBs and extended warranties (up to 10 years or 120K miles), because it is a known problem. At 165K, I'm not covered. Bummer.

    First though, I researched the problem, and made sure it was not another issue, and I did this:

    Throttle - I inspected the throttle. It is common that a sticky throttle can cause this. It is easy to get to and inspect. Search "Cleaning Prius Throttle" on Google.

    12VDC Battery - I replaced it with a new one, as mine was a few years old.

    Spark Plugs - I replaced them, it had been 100K miles so what the heck.

    Fuel Cleaner - I knew this wouldn't help but I put in a bottle of Techron, on the wild chance it was bad gas or could be cleaned out.

    Oil Change - I changed the oil making sure 5W-30 was used.

    None of this worked. I still had the error codes and fuel pressure problem. So I'm sucking it up, and my car is at the dealer getting repaired right now.

    I'm writing this up as an information dump to others who might be having a similar issue.
     
    #1 gerrypez, Dec 20, 2009
  2. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Owch! You have my sympathy but a couple of quick questions:

    • Did you clean the throttle or just use the sticky throttle check? The reason I ask is the intake manifold is heated. If tested after the vehicle had warmed up, the gunk might not have held the throttle plate so it could be felt. That is why I clean the throttle plate every Fall. I'll update my earlier postings.
    • Did the technician report the fuel pressure?
    GOOD LUCK!

    Bob Wilson
     
    #2 bwilson4web, Dec 20, 2009
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Sounds like you took most of the right steps. The fuel pressure spec is 43 psi, what pressure was measured?

    If fuel pressure is low, one other item to check is the circuit opening relay. If resistance exists across the switched contacts, that will lower the voltage applied to the fuel pump relay and fuel pressure will be decreased.

    The circuit opening relay is located in the relay box near the inverter. The procedure to check it is to remove the relay and apply 12VDC across the relay coil terminals, then measure resistance across the switched terminals using a digital multimeter. After subtracting the resistance of the multimeter test leads, see what the resistance is across the switched terminals. If more than 0.5 ohms, replace the relay.
     
    #3 Patrick Wong, Dec 20, 2009
  4. tochatihu

    tochatihu Senior Member

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    I understand that the work is already done, and hope the problem is resolved. Would only like to add that, according to the Prius parts list (available free online), the cost for the fuel tank assembly #77001-47071 is stated as $212.96 and the R&R time is 3.0 hours. There are other associated parts that might have needed to be replaced, but I would have been looking for a price about $500 for this work.

    Also, for the benefit of future potential victims, can you give any detail about the shop's mention of an extended warranty related to this? There is at least one related TSB (EG011-03) but it does not stretch the initial warranty periods.
     
    #4 tochatihu, Dec 20, 2009
  5. gerrypez

    gerrypez Junior Member

    Joined:
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    Location:
    Davis, CA
    Vehicle:
    2017 Prius Prime
    Model:
    N/A
    To answer the questions..

    - Fuel Pressure Spec is 43 psi, my car was measured at 32 psi.

    - It was not a TSB, but rather a letter I received directly from Toyota in Sept 2009, saying that these error codes are extended in warranty to 10 years or 120K miles.
     
    #5 gerrypez, Dec 24, 2009
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