Help! My prius thinks there is a door open.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Alan Clarke, Feb 18, 2020.

  1. Alan Clarke

    Alan Clarke Junior Member

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    I've got a 2005 prius, eveything was going great until Sunday, we were away for the weekend and on starting the car on Sunday morning the door ajar warning came on. I tried all the doors and made sure the boot/trunk was closed but nothing seemed to help. I had to drive home 1.5 hrs with the warning buzzer on constant. I have read a few of the similar posts on here, and can't find a remedy, I have removed the 12v battery, charged fully and refitted, but still no cure. Car had a new Toyota hv battery last May time and everything was going perfect.
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    Frequently caused by the rear hatch lid switch. You'll need to remove the rear floor cover and the black plastic storage tray to remove the trim piece that covers the latch assembly. Then check it out to see if it has debris or whatever preventing it from working correctly.
     
  3. Alan Clarke

    Alan Clarke Junior Member

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    Thanks, I have already checked, might have to get a replacement latch to see if it helps.
     
  4. valde3

    valde3 Senior Member

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    Turn the trunk light switch to ON (it only has off and on when trunk is open positions) and close the trunk does the light turn OFF in seconds? If not then you might need the new trunk latch (or something related to it).

    Check the lights on the bottom of front doors. When door is open light should be on. When door is closed light should go OFF. If it doesn't you will probably just need a new door courtesy switch for that door. Check that door open light is still ON when checking this.

    Open ONE of rear doors take the screw out of door courtesy switch. If door open light turns OFF you will probably just need that door courtesy switch. Do the test for both rear doors.

    Door courtesy switch is the rubber button that door presses when it's closed.
     
    #4 valde3, Feb 18, 2020
    Last edited: Feb 18, 2020
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  5. Alan Clarke

    Alan Clarke Junior Member

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    Hi all, the light on the drivers door is on constant, I swapped the courtesy switch with the one on the passenger door which i checked was working, as it turns the light off, on the door, did't help light is still on. Where do I go next? Is there a module controls this?
     
  6. dolj

    dolj Senior Member

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    Check to see why the switch is not activated??

    Out of interest, put an ohmmeter across the original driver's door switch and see if it breaks continuity when you press it in. I'd hate for you to throw out a perfectly good switch, just because you assumed it was broken.
     
  7. Alan Clarke

    Alan Clarke Junior Member

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    Already checked the switch it's working perfect, was hoping it was the switch, it would have been an easy fix.
     
  8. dolj

    dolj Senior Member

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    In that case, there must be something stopping the door from operating the switch as it is designed to.
     
  9. valde3

    valde3 Senior Member

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    So light didn't turn OFF even when courtesy switch was disconnected or you pressed it down? If it did then it could be a dent in the door/pillar that stops the door from pushing the switch in.

    If it didn't turn OFF measure the voltage at the switch. If there is voltage (12V?) it could actually be a bad control unit (body ecu) but this is very unlikely. If there's no voltage at the wire it's probably chafed at some point and touching the body round there. It should be the only violet color wire going into the body ecu. Wire should be violet the whole way and no connectors in it. You just need to follow the wire and visually check it. Fix is easy once you just find the bad spot.

    You cold also proof that the wire is bad by cutting it at body ecu end. That would then turn off the light at drivers door if the wire is bad. You could then fix it the hack way by just running the new wire from the body ecu to drivers door courtesy switch.
     
  10. Alan Clarke

    Alan Clarke Junior Member

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    thanks for the help, do you know the location of the body ecu?
     
  11. valde3

    valde3 Senior Member

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    Hybrid Control ECU location? | PriusChat

    So the light doesn't turn off even when manually pushing the door courtesy switch in?

    I think you should follow the wire from the switch end as chafing is much more likely to be happen there.
     
  12. Alan Clarke

    Alan Clarke Junior Member

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    Went out to work on the prius this morning and suddenly it's mysteriously fixed, maybe the Irish Leprechauns. lol
    We are having a lot of rain at the moment, could it be a water ingress problem affecting the electrics?
     
  13. valde3

    valde3 Senior Member

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    Could be. But it also could just be a that the chafed wire moved from where it's touching body ground.
     
  14. Alan Clarke

    Alan Clarke Junior Member

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    Oops spoke too soon, problem returned again.
     
  15. Alan Clarke

    Alan Clarke Junior Member

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    Could the boot/trunk latch cause the drivers door lamp to operate? I pulled the panels off and followed the violet wire, everything looks normal.
     
  16. Alan Clarke

    Alan Clarke Junior Member

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    Just took the car for a drive when I put the indicators on the door ajar was going on and off intermittently.
     
  17. valde3

    valde3 Senior Member

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    No. Light on the drivers door comes one when the body control ecu detects that the violet wire going to drivers door courtesy switch is grounded. Door courtesy switch ground the wire if nothing is pressing the door courtesy switch down.

    So light being on when door is closed means:
    -that door courtesy switch is not pressed down (dents etc.) easy to check by just pushing the switch down by hand
    -switch is bad (if you already swapped them around that shouldn't be concern)
    -wiring between the switch (violet wire) is grounded at some point
    -wiring to light is grounded at some point (door flex maybe) but I'm not sure this would cause the door ajar light to be on also
    -body ecu is bad (very unlikely)
    -power or ground to body ecu is bad (pretty unlikely)

    Check the voltage at violet wire?
     
    #17 valde3, Feb 19, 2020
    Last edited: Feb 19, 2020
  18. valde3

    valde3 Senior Member

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    You mean turn signals? Does this happen every time? Left and/or right turn? With hazard lights? Does the door ajar light blink at the same speed as turn signal bulbs? With them or opposite of them?
     
  19. Alan Clarke

    Alan Clarke Junior Member

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    Only happened with the turn signals once. I can't replicate it. It was blinking at the same speed as signals, I will check the violet wire for voltage.
    I got a cousin to put it on his diagnostic, it is showing drivers door courtesy switch on.
     
  20. valde3

    valde3 Senior Member

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    That sounds like a wiring harness issue as there the circuits for turn signals and door courtesy light don't share anything.

    Actually both of them use ground point IH https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&ved=2ahUKEwiP8pTIh97nAhVOaJoKHXCIBgEQFjAKegQIAhAB&url=https%3A%2F%2Fpriuschat.com%2Fattachments%2Fwiring-diagrams-pdf.22501%2F&usg=AOvVaw3ZLK8jnAB_TRAN298tHqfb page 58 of this manual shows where it is. Checking that might be a good idea.
     
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