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Error code P1437

Discussion in 'Generation 1 Prius Discussion' started by aswresm, Sep 4, 2014.

  1. aswresm

    aswresm Junior Member

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    Car jerks at traffic light stops and the BRAKE light illuminates and check engine came on with P1437 code....I checked with a scanner and it's either a vacuum problem , a gas pedal problem or a Catalytic converter issue.......
    I looked at the EVAP system and the vacuum lines ....Didn't see any damage .....
    Any idea please on how to fix this issue at it usually happens on stops ....

     
  2. wa-chiss

    wa-chiss Member

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    TIS says either:
    Vacuum lines leaking
    VSV (Vacuum Switching Valve) for HC Absorber and Catalyst system malfunction
    Vacuum sensor for HC absorber and catalyst system malfunction
    and/or the Check valve

    Start with the easiest and cheapest first. Double check ALL vacuum lines if you don't know which exact ones to check. You should be able to hear a slight "hiss" from the affected hose/port with the engine running.
     
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  3. aswresm

    aswresm Junior Member

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  4. aswresm

    aswresm Junior Member

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    I made some search and Now I think that my Prius is experiencing the Big hand syndrome.....Pedal replacement would be the solution...I hope!!
     
  5. Lubassoli

    Lubassoli New Member

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    Hi! Were you able to fix it? I’m having the same problem code p1437 w brake light on
     
  6. ronlewis

    ronlewis Active Member

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    That code is often associated with the exhaust VSV. It's a vacuum-controlled flap inside the catalytic converter cluster. The vacuum is stored in a round metal canister mounted on the cat. It's easy to see under the driver's side, you'll see the vacuum line dropping down from above. I didn't realize it also has a role in braking, as it describes, but that might explain your Brake alert. Here's a pic of it:

    Exhaust Brake Actuator Genuine Toyota 1723021010

    It has a rod that comes out of the canister and controls the flap inside the cat. That mechanism can stick, or I suppose the vacuum line can break and leave the flap in a fixed position, either open or closed. Which produces either a P1347 or P1348 (or is it 6?) depending.

    I don't think of Joshua Tree getting a lot of snow, but rust is usually the culprit. That's all I know, because I'm always removing that whole assembly and replacing with aftermarket, or a thief already removed it. My cars no longer have the flap, and I hack the code by installing a fake canister. Thus, I'm not sure if it's the actuator canister rod that sticks or the flap inside. My guess is that if the flap is stuck open, the exhaust takes longer to heat up the sensor, so the car may run rich/lean until it warms up, throwing the code. If it's stuck closed, the exhaust runs good until it's warm, then because the flap never opens, it runs warmer and warmer, eventually causing fuel mix issues that might not go away.

    So, maybe a new canister fixes you. Maybe a new cat, which is a hefty cost in CA. If it's the latter, I have used OEM cats with canisters for sale.
     
  7. ChapmanF

    ChapmanF Senior Member

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    Not long after I got my gen 1, I squirmed under there and wiggled that flap back and forth some and worked high-temp anti-seize in around the shaft. I don't know if that should get the credit, but I never did have any trouble with that valve.

    There are some threads here where people haven't been able to obtain that actuator, and have just sort of abandoned that system and connected the vacuum line to some vacuum actuator sold for a Honda Gold Wing. (When the ECM tries to move that valve, it wants to see the right changes of pressure in the vacuum line, so you can' just plug it or leave it open. The Gold Wing actuator behaves about as the ECM expects.)
     
  8. nolik

    nolik New Member

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    Дроссельная заслонка может заедать, у меня было такое, пошевели дроссельную заслонку, возможно поможет, либо сам механизм уже не работает, замени дроссель и проверь ушла ли проблема, если нет то ищи дальше. дроссель можно легко проверить компьютером, посмотреть, что происходит во время езды, видна ее положение
     
  9. dolj

    dolj Senior Member

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