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2009 Prius Gen 3 Engine High Revs Problem

Discussion in 'Gen 3 Prius Technical Discussion' started by yourebayexpert, Jan 16, 2018.

  1. yourebayexpert

    yourebayexpert New Member

    Joined:
    Jan 16, 2018
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    Location:
    Australia
    Vehicle:
    2009 Prius
    Model:
    i-Tech
    Hi Everyone
    I have a prius 2009 (i then gen 3 or Prius c "newer shape") 1.8L
    I picked this car up basically for a song but having a few issues

    When i purchased the car it has hybrid error all over tha dash and was lit up like a christmas tree (hence why i got it cheap)
    I cleared all the codes using my opcom and did a soft reset of the ECU and the problems went away and car drove fine for a week but then the "hybrid error" returned. T then removed the battery and thought i would check all the cells and all seemed to test OK even under load they were all over 7v. I put the battery back together and everything seemed to be fine for a couple of months (no more errors). Then one day i was caught in a traffic jam on the hiway bumper to bumper and the car battery went flat and then when i went to accelerate the engine made a terrible rattle sound (almost like a loose chain) and the hybrid error returned. I cleared the codes and it has not returned again but i am experiencing some strange behavior

    here is a list of whats happening

    * If the hybrid drive battery goes flat and you are at a craw when you go to accelerate the car makes a terrible rattle (it will do this both when the car is COLD or has been running) it does not seem to do it all the time but is intermittent (yes there is oil in the car)
    * If the battery is low the car seems to REV very high and has absolutely no power, you can stomp on the accelerator and it will rev but will not pick up speed fast at all.
    * If the battery in the car is low when you start it the car will rev high even when the battery is nearly full and lacks power. i have noticed also when you look at the fuel meter (the one that shows liters per 100/k) it can drop back to zero like its running on battery but you can feel and here the engine still running quite high. It will keep behaving like this until you turn the car off and start the car again

    I have checked the car while going for long drives with my bluetooth opcom reader and it does not appear to be getting hot or anything

    I have played with cars my whole life (im actually an expert on the Z22SE engine and have rebuilt over 300 of them) but have absolutely no idea about these hybrids even where to start

    Anyone know what the issue might be? happy to answer any questions
     
    #1 yourebayexpert, Jan 16, 2018
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome!

    how many miles/km on her?
     
    #2 bisco, Jan 16, 2018
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    yourebayexpert,

    Your "rev"ing symptoms are pretty typical for what happens when a battery is showing 2 (purple) bars or if has a 'red triangle of death' due to a weak battery.

    I've done many load tests on recently built, healthy batteries and typically drain them down to about 40% capacity (2 purple bars, sometimes 1 purple bar). Then when you go to drive the car, it acts extremely weak. This is because the electronic controls do not want the battery to be that low and will severely limit the current draw allowed from the battery until it is charged back into the 'blue bar' area. If your battery is being drawn down due to AC running, or something similar during very low speed operation, the engine will normally cycle on and off to keep the battery charged slightly above 2 purple bars. It will start the engine as soon as it drops to 2 bars and typically shuts off the engine as soon as it reached 3 bars, sometimes 4. If you happen to be at the 2 bar area when traffic clears up and you try to accelerate, it will act like a dog. Been there many times. You can help this situation a bit by not running the AC on high, just drop it down to a low/middle speed and the battery lasts much longer.

    As for the rattle, I've experienced a handful of cars that get pretty noisey when the battery is drained into that low area. I've also experienced some noisey cars that just have an old weak battery. Typically, the noise clears up quite a bit when the battery charges. I've also had noises go completely away after installation of a replacement HV battery. Source of the noise? I haven't dug into it to find out, honestly.
     
    #3 TMR-JWAP, Jan 16, 2018
    kc410, qettyz and SFO like this.
  4. kc410

    kc410 Active Member

    Joined:
    Nov 26, 2013
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    Location:
    2010 Prius IV
    Vehicle:
    2015 Prius
    Model:
    Four
    My 2010 (at ~220K) was doing this rattle . When I cleaned the entire EGR circuit I found the EGR cooler was completely plugged. After installing a clean EGR cooler the rattle ceased to appear. I have even tried to reproduce the rattle now (by running the traction battery down to 2 bars & then accelerating briskly) & the engine will not rattle.
     
    #4 kc410, Jan 18, 2018
    Raytheeagle likes this.
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