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I think my Prius not starting is going to be much different than the other posts here...

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Bulbuh16, Dec 9, 2018.

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  1. Bulbuh16

    Bulbuh16 New Member

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    Here is the situation: I had a bad evap core coil, and the dealership wanted $4000 to fix it on my 2005 Toyota Prius. Hard NO. So I am a mechanic of another trade, so I buckle down and go to the Toyota tech site, grab the manuals, and take about a month to do it. Just a little bit each day and time change really sucked because it took away my daylight(but gave me cool days in Florida to work!).

    Anyways, that’s all changed out, including the heater core by recommendation of every friend I have. Pressure tested, vacuum pulled, and charged. I set out to put the whole car back together this past weekend.

    Wouldn’t you know it? I have power(12.2v tested) at the battery, lights work, dash lights work, horn works, remote unlocks and locks, etc...but the car won’t power on at the ignition switch!

    I mean there are no lights when I push the power button. The car whirs when I push the brake in like normal, but brake pushed or not, key inserted or not, the power button does jack. The MFD stays black too. No sign of life.

    I have pulled the dash back apart to find a missed connection SOMEWHERE, and I have come up with nothing. I was very meticulous, took picures, and checked everything! I’m going crazy. What could cause a non responsive power button that didn’t give issues before?
     
    #1 Bulbuh16, Dec 9, 2018
  2. tankyuong

    tankyuong Senior Member

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    Try a new 12v battery
     
    #2 tankyuong, Dec 10, 2018
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. Put a charger on the 12V battery as 12.2V is very marginal.
    2. Look at the wiring harness associated with the POWER button, for damage to the switch or the wiring associated with removal and installation of the dashboard.
    3. Check the 20A HEV and 15A AM2 fuses. Remove each fuse, and measure continuity using an ohmmeter, do not rely upon visual inspection.
    4. Do you have the Smart Entry/Smart Start system? If yes, make sure the fob has a good CR2032 battery in it.
    5. When you depress the POWER button, does the LED light within the button do anything or does it stay dark?
    6. If you really can't find an issue, you are going to have to dive deeper by studying the electrical wiring diagram further.
     
    #3 Patrick Wong, Dec 10, 2018
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  4. The Electric Me

    The Electric Me Go Speed Go!

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    I'm concerned about this....

    So while you're executing this repair project, basically it's not being run or driven? That's a 14 year old Prius not being driven. So hopefully, it is as simple as the 12 volt battery.
    But that's also a 14 year old Hybrid Battery.
    Did you disconnect the Hybrid Battery during your repairs?
    I know there is an safety interlock that can cause a lot of problems if not properly put back.

    Anyway, others have better advice than I.
    Objectively, from a distance, this looks like the type of problem that could be "simple"--once you discover it, OR quite a bit more complicated and expensive, if it turns out to be Hybrid Battery failure related.

    I'm hoping for all the potential options that are "simple".
     
    #4 The Electric Me, Dec 10, 2018
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  5. bisco

    bisco cookie crumbler

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    if it isn't the 12v or the safety interlock, it could be a dead hybrid battery cell as electric me mentions.

    you'll need tech stream software to check the trouble codes
     
    #5 bisco, Dec 10, 2018
  6. ChapmanF

    ChapmanF Senior Member

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    It could also be AN ASTEROID AND WE'RE ALL GONNA DIIIIIIIEEEEEEEE!!!!!1!

    I would relax .... if there's enough 12 V to light and run other things, but the power button won't power the car on, there's probably quite a simple explanation not far from that button or the related ECUs.

    Once that's solved and the car can be turned ON ... if there's any issue with, say, the traction battery, it will say so, with readable trouble codes. If it doesn't, enjoy the car.

    -Chap
     
    #6 ChapmanF, Dec 10, 2018
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  7. jerrymildred

    jerrymildred Senior Member

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    If 8.5 volts wold start my '05 when the aux battery was dying (with no codes), I'm sure 12.2 will start yours.

    I assume you had lots of stuff behind the dash disconnected when replacing the heater core. It sounds to me like something didn't get reconnected or got connected wrong. Techstream might get you aimed in the right directions, but the odds are you'll have to take apart the dash to find and fix it.
     
    #7 jerrymildred, Dec 10, 2018
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  8. Bulbuh16

    Bulbuh16 New Member

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    So I did nothing to the hybrid battery, and I did disconnect the 12v battery during repairs which only took about a month. And the hybrid battery was actually replaced about 18 months ago by the dealer before I bought it. That was the biggest selling point for me when I bought it. Again, 12v battery tested out fine.

    And I am going to be completely honest. There is a post buried on this site about this type of job that says it is absolutely not a DIY job. And it isn’t. I have more tools than most because I used to do HVAC field work, and now I just do sales. Step 1 is disconnect the battery. Step 2 is remove EVERY DAMN THING under the dash. Replace cores, and put everything back the way it was because it won’t fit otherwise.

    Error codes? None. Again, power button doesn’t do anything. The car doesn’t start or even go into standby mode.

    I did actually do the “jump start” procedure for a Prius as Toyota explains it. I let it trickle and then turned off the “jump vehicle.” Left it connected and it still does nothing.

    The key FOB is fine. Unlocks and locks the doors, red light flashes on it, and the doors unlock when the key is just on my person and I pull the handles on the driver’s door and back hatch.

    The Power push start ignition switch, or whatever we want to call it, stays completely dim. No lights of any sort. I will say that I did order one off eBay coming next week, and I hope that’s all it is. If not then we are still looking at a possible missed connection.

    I have also tried the various videos that tell you how to reset this and that by holding the power button, then a double tap, then hold a brake and flick the lights 3 times, clap your hands 3 times, draw a pentagram under the hood, etc. None of that really seems to have any effect on it, negative or otherwise.

    I can definitely check all my fuses for continuity when I get home.

    As far as the battery goes, the way I understand it is that 12v +\-.02v is actually a decent read considering the vehicle isn’t running. It’s not a normal car battery, so that is why that read is standard. If it needs to be stronger than that, I haven’t read that anywhere.

    Also, I only bought the 2 day Toyota tech sub(which is expired by now :/). I did not download the wiring diagram for my year Prius. If anybody has that I would be eternally grateful.

    Thank you ALL for the quick replies and consideration while I was asleep last night.
     
    #8 Bulbuh16, Dec 10, 2018
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  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    A new, fully-charged 12V AGM battery should measure 13.0V. Your battery is close to discharged, hence my suggestion that it would not hurt to charge it now.
     
    #9 Patrick Wong, Dec 10, 2018
  10. PriusCamper

    PriusCamper Senior Member

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    Assuming you have a second vehicle you can add the power of an additional 12v battery to ensure that's not the issue... Basically what's going on is there's a start-up sequence of the vehicle and there's a point in that start up sequence that fails.

    Most of us are familiar with home computers rebooting in a safe mode where you can watch it boot up line by line. Not sure if Tech Stream has that function, but that's how you'll zero in on it...

    Also I doubt it's the problem, but if you pull off the left side rear panel, unbolt right rear seat back and uncover the connections to the HIgh Voltage pack you can get a current voltage reading on your pack to ensure everything is ok with that.

    Lastly are you certain there's no error codes? Some OBD2 readers can't check subcodes...
     
    #10 PriusCamper, Dec 10, 2018
  11. zeron1982

    zeron1982 Junior Member

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    Put the remote control in the slot, keep your feet away from brake and gas pedal , push the power button once see what happens give it 5 seconds then push it again wait 5 seconds, it will go to ignition mode then push the brake pedal all the way and power button, the car should stay on or shut down, now you know if it's a electrical or mechanical issue,

    Posted via the PriusChat mobile app.
     
    #11 zeron1982, Dec 10, 2018
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  12. TMR-JWAP

    TMR-JWAP Senior Member

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    If the dash lights work, as stated in the first post......yet the power button displays nothing on it's led, why in the world are we discussing the HV battery...at all?

    Approach the car, look in the window...the little car symbol with key should be flashing.
    Touch handle...door should unlock
    Open the door, the door ajar light should come on...
    The power button should have no LED lit
    With foot off the brake, press power button one time..the led light should turn green..the MFD comes alive and the radio comes on..etc
    With foot off the brake, press power again, it should turn red and the dash comes alive.

    Yet...OP states that regardless of what he does, or what order it's done, no LED lights on the power button....

    In order for a physical button to work, (ie..pass a signal through itself) it has to have a signal (power) on one side of it. Does it have power on one side?

    Maybe it provides ground to a ecu terminal. Any chance a ground wire isn't connected?

    I'll look in my book when I get home to see if I can find the switch schematic..
     
    #12 TMR-JWAP, Dec 10, 2018
    Last edited: Dec 10, 2018
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  13. ChapmanF

    ChapmanF Senior Member

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    Thank you for redirecting focus to the problem at hand.
     
    #13 ChapmanF, Dec 10, 2018
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  14. bisco

    bisco cookie crumbler

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    <popcorn emoji>
     
    #14 bisco, Dec 10, 2018
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  15. Bulbuh16

    Bulbuh16 New Member

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    Ok so first, thank you! I can do everything you are saying up until...you guessed it. The power button. Foot off brake, on brake, key inserted, etc. It gives no reaction or indication.

    HOWEVER, you just made me think to check to see if I have low voltage going to at least one side of the pins. I think it’s an 8 pin. I’m going to check that.
     
    #15 Bulbuh16, Dec 10, 2018
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  16. PriusCamper

    PriusCamper Senior Member

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    Your popcorn emoji didn't work... Why not?
     
    #16 PriusCamper, Dec 10, 2018
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  17. The Electric Me

    The Electric Me Go Speed Go!

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    You're being sarcastic...but Dinosaurs?
    Bruce Willis in Armageddon....

    An Asteroid and we're all going to die, -actually possible.

    I now return you to the Holiday Season in progress...
     
    #17 The Electric Me, Dec 10, 2018
  18. bisco

    bisco cookie crumbler

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    i don't have one :whistle:
     
    #18 bisco, Dec 10, 2018
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  19. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

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    Will this do?

    upload_2018-12-10_20-45-19.gif
     
    #19 Prodigyplace, Dec 10, 2018
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  20. Bulbuh16

    Bulbuh16 New Member

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    Ok so from my left to right, these are the wires I have. Green, yellow, black and white(one wire), black, red, free space, green again, and white.

    I’m assuming black is my hot because it’s the only that gave me any read at all when testing to ground. Black reads 12v when being tested in conjunction with “black and white” and white. Nothing really gets a hot read otherwise. I imagine that’s going to be me saying that the plug DOES have power. Unless someone says otherwise.

    I’m going to post again with an update on the plug. It is a little hard to test, but I’m going to give it a go.
     
    #20 Bulbuh16, Dec 10, 2018
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