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Idle system problems - HELP!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Comache, Sep 11, 2014.

  1. Comache

    Comache Junior Member

    Joined:
    Sep 11, 2014
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    Location:
    Bucharest, Romania
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hello,
    I own a Prius 2 from 2004, 122.000 km.

    A few months ago the engine light on board light up and turned off a couple of time after a day or something or around 45-50km.

    Two month ago the engine light turned on again and never turned off.

    At the service garage they told me that it is possible to be the idle system sensor.

    Today i came to a garage to clean the sensor and after that the cleaning the sensor turned off, but after 5km the sensor came back. I stoped the car, turned it off and started the engine again after a few minutes. The sensor light was still on. I drove the car for about a couple of km when i felt that the car did not accelerated, even with the pedal pushed to the ground.

    I stoped the car again and turned it off and on. Everything came to normal except the engine light wich was still on. In 20 km to the home that pattern happend again two times.
    At home i stopped the car for about half an hour. After that, when i started the engine again, the engine light was off but after about 5 or more km lighted up again.

    But i noticed a pattern.
    After i start the engine, the car was working properly until the battery was loaded almost full (blue bars, not until green change). At this moment, the termin engine seems somehow stop working, thus running only on EV. This is strage because at some points i could hear the engine working lightly witouth showing on the monitor that it is working or loading the main battery.
    At this point, while main battery was quickly discharging, the car was loosing power and acceleration, until the main battery shows one or two red bars. At this point instopped the engine, turn the car off and on again and the cycle starts again, with engine functioning normally but the pattern repeating as described above, again and again. After the termic engine seems to stop it draw my attention that the rear seat exahaust from the main battery was blowing air like the fan was working on full speed.

    After i stop the car for more than 30 minutes the engine light goes off and the above cycle of symptoms starts again.

    I also noticed that in parking mode but preasing the acceleration pedal to the bottom and keeping it like this, the engine accelerates but accelerating and decelerating regulary like a sinusoidal wave.

    Please help with any advice you have or if tou encounter this problem.

    Thank you.
     
    #1 Comache, Sep 11, 2014
  2. valde3

    valde3 Senior Member

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    Location:
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    Vehicle:
    2004 Prius
    What do you mean by idle sensor? Actual code(s) would help a lot for diagnosing it.


    It sound like whatever they cleaned just needs to be replaced. Maybe throttle body?


    Prius can spin the engine without actually using it to produce power so it’s likely that it was doing that when engine was just spinning but not shoving on the screen. If that’s first time engine is turning of then it’s likely that after engine turnoff it’s just confused or can’t get throttle to correct position to start it hot.

    If air inlet in the side of the rear seat is plowing air out your battery cooling fan is running in wrong direction which will make hv-battery cooling worst and hv-battery life shorter.

    That does sound like throttle body problem. Even if I haven’t seem Prius with throttle body problems.
     
    #2 valde3, Sep 11, 2014
  3. Britprius

    Britprius Senior Member

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    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    You need to get the fault codes read and post them here before any reasonable diagnosis can be given. Telling us what country your in and your location would also help.

    John (Britprius)
     
    #3 Britprius, Sep 11, 2014
  4. Comache

    Comache Junior Member

    Joined:
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    Location:
    Bucharest, Romania
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hey,
    Error code is P0505

    I am in Bucharest, Romania.
    I forgot to tell about high oil consumption since the engine light came on.
    The car had the last oil change in september 2013 at 110.000. In march I added around 2L of oil because it was a bit under the minimum level. Now the level, at 120.000km is under the minimum level again. Tomorow in the morning I will go to change oil and filters and after that I'll go back to my Toyota mechanic to check again the idle sensor.
     
    #4 Comache, Sep 11, 2014
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    DTC P0505: Idle Air Control System. This is logged when the actual engine idle speed varies more than 200 RPM from the target speed, five times during a driving cycle. Here is a list of potential problems causing this:

    Electric throttle control system: Clean the throttle body interior and throttle plate using throttle body cleaner sprayed on a clean cloth. Remove the air cleaner housing for access. Rotate the spring-loaded throttle plate shaft when the Prius is IG-OFF to make sure it moves freely.
    Air induction system: Look for unmetered air entering after the mass air flow sensor mounted on the air cleaner housing. Check the tightness of the clamp that secures the bottom of the air cleaner housing to the throttle body.
    PCV hose connection: Look for a loose or leaking hose
    ECM

    If you go through this list and don't find any problems, the throttle body will need to be replaced.
     
    #5 Patrick Wong, Sep 12, 2014
    Britprius likes this.
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