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How long will prius crank if no start is detected?

Discussion in 'Gen 2 Prius Main Forum' started by Prius92, Jul 31, 2024 at 9:59 AM.

  1. Prius92

    Prius92 Member

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    Swapped a replacement engine. I think the hybrid battery might be low.
    Go to start it, all I get is a clunk and nothing. Won't even turn over.
    If the engine had been sitting a while, could it need rotated by hand to free anything up?
    I've asked 2 dealers how much it would cost to have the hybrid battery charged, but they all keep telling me "the 12v battery starts the car" which isn't correct.
    So my question is, say you took the injectors and plugs out, how long would it try to rotate it before stopping?
     
    #1 Prius92, Jul 31, 2024 at 9:59 AM
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    If the car goes to ready condition, and you hear a clunk as the engine tries to start, you have a big problem. Something in the driveline (engine or transaxle) is seized and preventing the engine from turning.

    Did you turn the new engine by hand prior to installing it? I have a spare engine, still mounted to its transaxle, slated for installation this fall, and I can rotate it with a socket/ratchet with very little effort.
     
    #2 TMR-JWAP, Jul 31, 2024 at 12:45 PM
  3. Prius92

    Prius92 Member

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    So there was a cylinder stuck. I got it freed.

    But have another issue...I think the hybrid battery ran out.

    Oddly, when you go to start it after reconnecting the 12v, it shows full bars, then within 5 seconds floats down to 1 bar.

    It ran about 2 seconds then stopped.

    Other odd thing, the ready light flashes.

    I'm going to hook up my bluetooth scan tool later and see what's up/
     
    #3 Prius92, Jul 31, 2024 at 4:43 PM
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    That's a strong suggestion that the hybrid battery can't hold much of a charge anymore, it's toast.
     
    #4 Leadfoot J. McCoalroller, Jul 31, 2024 at 5:23 PM
  5. Prius92

    Prius92 Member

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    Now what?
    Is it going into some kind of failsafe mode?

    Seems to be stuck to the 1 low voltage module.
    The others look good, so it appears to be affecting the SOC.




    [​IMG]
     
    #5 Prius92, Jul 31, 2024 at 5:55 PM
  6. Brian1954

    Brian1954 Active Member

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    Use a volt meter to measure the total HV battery voltage and compare it to what is being shown in the Dr. Prius app (201.59v). If you measure about 201.59 volts, you need to use a grid charger to charge the HV battery.
     
    #6 Brian1954, Jul 31, 2024 at 6:36 PM
    Last edited: Jul 31, 2024 at 7:00 PM
  7. Brian1954

    Brian1954 Active Member

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    When you disconnect the 12v battery, the HV battery SOC is erased from the hybrid control ECU. When the 12v battery is reconnected, the hybrid control ECU uses a default SOC of 60% until the ECU has time to recalculate the actual SOC again. So after recalculating the SOC, the battery graph goes down to 1 bar. This is telling you that you have a very low SOC in the HV battery. It does not mean that your HV battery is bad.
    The car is not running during those 2 seconds. The electric motor is trying to start the engine for those 2 seconds, but it is not running.

    Have you tried using a scanner to check for trouble codes?
     
    #7 Brian1954, Jul 31, 2024 at 6:54 PM
    Last edited: Jul 31, 2024 at 7:08 PM
  8. Prius92

    Prius92 Member

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    A couple codes related to the throttle position sensor, I'm not sure if I hooked it back up right, could that cause an issue?
     
    #8 Prius92, Jul 31, 2024 at 8:07 PM
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