Help...I need some advice with no start issue!

Discussion in 'Gen 2 Prius Main Forum' started by StephenJ, Aug 22, 2025 at 3:51 PM.

  1. StephenJ

    StephenJ Member

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    I cleaned the tb last night, but it wasn't too bad and seemed to be operating fine. But the biggest issue right now is the engine isn't being turned over to start up.
     
    #21 StephenJ, Aug 26, 2025 at 7:52 AM
    Last edited: Aug 26, 2025 at 8:02 AM
  2. Tombukt2

    Tombukt2 Senior Member

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    That's right it will not until you see the words or the letters r e a d y. On dash . When you do attempt to push the brake and push the button do you hear the relays clicking behind your head in the trunk it's pretty loud click click click or click click . Listen carefully . You will hear them or you will not it's important to note if you're getting the relays opening closing and opening back up again that has to do with readying vehicle .
     
  3. bisco

    bisco cookie crumbler

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    it seems to me (and i could be wrong) that the engine not starting would not prevent the car from making 'ready'. that would be more of an electrical issue i think.
    perhaps the hybrid battery level is too low from cranking the engine?
     
  4. Tombukt2

    Tombukt2 Senior Member

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    Clicking in the back of the car when you're trying to make ready do you hear the clicking those. You should be able to be ready even with a low hybrid battery it should attempt to do something it shouldn't lock you out
     
  5. Brian1954

    Brian1954 Senior Member

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    Try scanning for codes again.

    What scanner are you using?
     
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  6. ChapmanF

    ChapmanF Senior Member

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    Right. The startup sequence is READY lights up first (and you can drive away if you want, under electric power, as soon as it does). The engine cranks a bit later if the car calls for it.

    If the cranking is unsuccessful, some codes including P0A0F will eventually be logged and the triangle pops up. (I don't clearly remember whether the READY word goes out at that point, or the car just continues to say READY with the triangle showing, and won't go fast.)
     
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  7. StephenJ

    StephenJ Member

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    So it does make a relay clicking sound, however I'm not sure that it's all of the clicks. I was trying to find a video where I can hear exactly how they should sound to compare but couldn't find one. So its supposed to be 3 distinct sounds? I'm not at the car, it's at my brother's house, however I think it only made 2 sounds, but I'll go by there this morning and listen.

    Thanks,
    Stephen
     
  8. Tombukt2

    Tombukt2 Senior Member

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    [email protected] I'll send ya a bite of readying it's easier than posting vids and bites on the chat I think . see another Prius in town at the whole foods just walk up to the person and ask him to sit in the car and push the start button while you put your ear to driver quarter panel . Tell the other car owner you're not a weirdo you just wanna hear something . They'll be happy to do it.
     
  9. StephenJ

    StephenJ Member

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    Using a nice professional Autel scanner, however I also have a old version of Techstream I can hook up to it if I can find the laptop lol. I haven't used it in a long time.

    HOWEVER, the last time I had it running I had cleared the codes then I turned it off and went to turn it back on and that's when it wouldn't turn back on, it doesn't go into "ready". If I turn the car to on where all the lights come on, it's not triggering any codes at all....
    I just sent you a email! You might want to edit your post to remove your address, I'm sure some boys will pick it up and start spamming you to death!
     
  10. StephenJ

    StephenJ Member

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    Also if it helps, when I hit the power button twice to turn the car on, I'm only getting 2 clicks in the back, a louder click then instantly a little more subdued click, kind of like 'tick tock'.
     
  11. Tombukt2

    Tombukt2 Senior Member

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    If you hit the power button twice with no pedal you should get a full display.
     
  12. Tombukt2

    Tombukt2 Senior Member

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  13. StephenJ

    StephenJ Member

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    If you mean the display up front, yes I get all the displays light up. Basically when I click power twice with or without the brake, I get all the lights on the dash and the center display all come on, and I get 2 fast click sounds in back......but the display never goes to "ready".
     
    #33 StephenJ, Aug 27, 2025 at 9:35 AM
    Last edited: Aug 27, 2025 at 10:49 AM
  14. Tombukt2

    Tombukt2 Senior Member

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    To be clear with two. Presses twill never ready. From the accessory state you would push brake and button 1 more time and ready
     
  15. StephenJ

    StephenJ Member

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    Okay, updates.....sounds like 2 issues....

    Issue 1....I opened up the back where the hybrid computer is and noticed I've got voltage on the battery side but not on the car side leads. I smacked the computer some and now it goes into ready mode and on the display it started showing more bars on the battery and the engine cranked up. So I'm thinking the hybrid computer is flaking out.

    Issue 2....it was running like crap and it threw code p1121....so I tested the coolant valves and one of them isn't working. I read that a stuck coolant valve can cause the throttle body to not run right.

    ****Can anyone give me advice on a stuck coolant valve? If I unplug the valve should that help the throttle body so I can test it and verify that the valve is really the issue?

    Thanks!
     
    #35 StephenJ, Aug 27, 2025 at 11:43 AM
    Last edited: Aug 27, 2025 at 12:11 PM
  16. Paul Gregory

    Paul Gregory Senior Member

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    It could be a problem with the hybrid control computer,
    or whatever it's called.
     
  17. StephenJ

    StephenJ Member

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    I have access to a prograde Autel I was using and I also have a laptop with a old bootleg Techstream. I finally got it cranked and it threw a code p1121 and it looks like one of my coolant valves is stuck because trying to activate them I can't hear one of them.
     
  18. StephenJ

    StephenJ Member

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    Another update....Ive noticed that it seems like it's rough when the display shows that it's trying to charge the hybrid battery.

    Could all this roughness I feel be the electric motor? Is there a fairly easy way to test the electric motor? What does the car feel like when the elec motor is dying? Does it make it feel like the engine is misfiring?
     
  19. bisco

    bisco cookie crumbler

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    if you are making ready again, shouldn't it be setting codes?
     
  20. ChapmanF

    ChapmanF Senior Member

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    You probably read that in a post from someone who was confused. P1121, like all P1 codes, is manufacturer-defined and can mean totally different things in different cars. In a Prius, it's about the Coolant Flow Control Valve Position Sensor Circuit, plain and simple, full stop. But there are other different cars where the same code has to do with the throttle body. Not in a Prius.

    Some simpleminded scan tools or lists of codes online just smash together all the things the code can mean in all different cars, instead of being useful and showing just the meaning for a Prius. Then people get confused and start trying to imagine some actual connection between the valve and the TB to 'explain' the happenstance use of one code to mean different things in different cars.

    [​IMG]

    There are two electric motors. Sometimes it can be useful to depart from the usual troubleshooting procedures and pursue some speculative or off-the-beaten-path idea, but it's usually hard to do that in a useful way without having a very accurate mental picture of how the car works, like the kind you would get by taking substantial time out to closely study the New Car Features manual.

    Toyota Service Information and Where To Find It | PriusChat

    One of your earlier posts mentioned P3190, a code the Engine Control Module sets when the engine is running very poorly for some reason (pretty much, any of the possible reasons a good old-school gasoline engine mechanic would think of checking for).

    When there's an engine problem, the usual reason for it to be rougher when the display shows charging (I assume you are comparing the roughness at standstill, between idling and charging) is that charging puts more load on the engine than idling. There's not a lot more to it, so it sounds like, for now, the usual troubleshooting steps for a poorly-running engine will be more useful than pursuing some more obscure idea.
     
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