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Driver side door always open – perma grounded

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Braveslice, Aug 20, 2020.

  1. Braveslice

    Braveslice Junior Member

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    Hi!

    My driver side door open sensor wire is permanently grounded. That is, when removing door sensor and measuring resistance between the wire and chassis, it is short circuited.

    What I am supposed to do next? I have no idea. Getting this far took lot of reading on chat already :D

    - Ajar is always on
    - Removing sensors from doors, or trunk connection does not remove ajar waring
    - Battery runs out in day or two
    - Indoor roof light stays on


    Yours,

    Braveslice
     
  2. sam spade 2

    sam spade 2 Senior Member

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    First you need to determine what the "closed" position of the switch should apply to the wire.

    Like you, I would assume that it is NOT supposed to show a ground if there is only one wire and the switch is removed from the metal body.
    BUT.....misunderstandings sometimes cost a LOT of time and money.

    If that ground is not supposed to be there, then you need to physically trace the wire and that might not be easy.
    The wire itself might be pinched and grounded.
    Or the device at the other end of the wire might have failed and IT is now grounded.
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    Temporarily, to save your battery while repairing this, turn the indoor roof light slide button to the center position so it stays off. Then remove the bulb from the driver door courtesy light. At least then you'll not have to worry about the battery draining.
     
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  4. ChapmanF

    ChapmanF Senior Member

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    For Finland, I think toyota-tech.eu is where you would go for to access the Electrical Wiring Diagram. It's interactive, you can click on that switch (or any other part of that circuit) and it will highlight where the wires are located, the connectors they run through, and the color codes of each segment.

    If Gen 2 routing is like Gen 1 and Gen 3 that I'm familiar with, that door wire is probably part of a harness running right along your driver door sill, forward to a big junction connector under the plastic kick panel at the forward corner of the door, where it plugs into the instrument panel harness. Unplugging that would be a handy way to get access for a multimeter to decide which segment has your ground fault.

    There can be multiple plugs at that junction. The wiring diagram viewer will show you which one to unplug and which pins are the ones for your circuit, once you have selected that circuit. It will look sort of like this (this is a recycled picture from another project—these aren't the pins you're looking for*).

    junc.png

    * they are the pins for the gen 3 hatch release button, if you ever want to add a hatch release at the dash of a gen 3. (I had a friend who was Lyfting and wanted to open the hatch for passengers without getting out every time.)
     
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  5. edthefox5

    edthefox5 Senior Member

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    What color is the wire that's grounded? Is it light green? I think i found it in the manual.

    So with the door open you can open and close the window by pushing the window up/down button?

    Is this a salvage title car or has had body damage from an accident?

    My guess is its pinched going through the rubber door bellows area. Is the bellows intact?

    That green wire goes to pin 25 on the body ecu. Body ecu is behind the drivers side left ac vent..
     
    #5 edthefox5, Aug 21, 2020
    Last edited: Aug 21, 2020
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  6. ChapmanF

    ChapmanF Senior Member

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    The way I read the original post (which could be my mistake), I thought it was about the door-is-open switch, which lives in the body B pillar, not in the door, so its wire wouldn't run through the door's rubber snoot. Just along the body down under the door sill trim.
     
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  7. Braveslice

    Braveslice Junior Member

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    Thank you for your great help and support!

    Lights are now off, the connector of door courtesy light removed, also I´ll keep battery disconnected if longer time no driving. A bit cable tracking done, and principle of door sensor studied. Door sensors break the circuit when door is closed.

    ChapmansF’s interpretation is correct, I included some photos about it.

    The case got different though, and door is not short circuited anymore, however door open warning light is still on.

    1. When 12v battery negative terminal was removed – door wire was not short circuited to chassis.

    2. When re-plugged 12V battery – there was 130 ohm ‘short circuit’ from door wire to chassis.

    3. When I removed large connector (in picture) and then reconnected I get infinite resistance between wire and chassis, regardless if 12V is connected or not. This might be because I might have broken the door wire cable or because something else. But no short circuit anymore.

    Can this be the case of bad ground connection somewhere else? Maybe related to body ecu edhtefox5 mentions…

    The has been 2 cases of mystical electronics operations during last 6 months. 4 Months ago, radio decided to change channels by itself 2 days in a row then it stopped. One month ago, when going slowly backwards, I put forward gear on and I got red tringle of death. After parking about an hour, it went away, but after that it happened to me 3 times before I realized that for some reason Car has become more sensitive when changing from reverse to forward.

    Also, sorry my English if not clearly written I am happy to write again.

     
    #7 Braveslice, Aug 22, 2020
    Last edited: Aug 22, 2020
  8. edthefox5

    edthefox5 Senior Member

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    Hmm interesting.

    Instead of measuring ohms to ground with 12 volt battery connected measure dc volts to ground on that wire in question.

    It may be a pull up circuit.
     
  9. valde3

    valde3 Senior Member

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    Drivers door open switch is directly (through connectors) to body ecu and brake power supply (the box next to 12V battery). Value changing with 12V battery being connected or not indicates that wire is not directly touching ground. It has to be touching a wire that is grounded with 12V battery connected or fault has to be related body ecu or brake power supply.

    But first check the voltage of the wire when your checking stuff with 12V battery connected. What do you get? Value of less than 0,2V or value of 0,6V or more could indicate something different so post the voltage here.

    Maybe disconnect the connector from brake power supply and see if the voltage still remains the same?

    Where in the Finland are you located? Maybe I could take a look at this just out of curiosity?

    No. Ecu pulls the wire up. Door open switch pulls it down. But yes voltage measurement would be much more useful.
     
    #9 valde3, Aug 22, 2020
    Last edited: Aug 22, 2020
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  10. edthefox5

    edthefox5 Senior Member

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    Sorry yes I meant pull down its voltage the door switch grounds it pulls it low.

    Probably a bad door switch not grounding completely. Corrosion maybe or loose screw..

    First door button post though I have seen.

    Its that light green wire in that blue connector he unplugged. I would just cut that wire about a foot from the connector plug in that connector and ground that wire see if it fixes the issue. Then you know its not the ecu/dash side its from there to the door switch side.

    Then when done butt it back together
     
    #10 edthefox5, Aug 22, 2020
    Last edited: Aug 22, 2020
  11. valde3

    valde3 Senior Member

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    Switch pulls the wire to ground when door is open. So bad ground at a switch could not cause this. Grounding happens though the bolt that the switch is attached. So if the OP is measuring it with the switch removed like first message says it can't be a bad switch.
     
    #11 valde3, Aug 22, 2020
    Last edited: Aug 22, 2020
  12. edthefox5

    edthefox5 Senior Member

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    That's how the switch is grounded. CORROSION MAYBE LOOSE SCREW as mentioned in post #.10

    he see's 130 ohms to ground at the switch with door open. It has dc on it hes in ohms his meter is confused. Thats why the 130 to ground goes open when the battery is unplugged.

    With door open measure the light green wire at plugged in blue connector probe that wire in the connector with dvm set to dc. It has dc on it. Probably 5 volts. if you pull that 5 volts to ground the door will show closed.
     
  13. ChapmanF

    ChapmanF Senior Member

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    If you pull it to ground, the door will show as open. That's what the door switch does, in the door-open position.

    Sometimes a flashback to the original post is in order ... the original poster came here because the door was being shown as open, when it was closed.

    There might be some jargon effects going on, because of the way switches are also described as 'open' or 'closed'.

    The door switch is a normally-closed switch that is held open when the car door is closed.*

    When the car door opens, the switch closes, pulling its circuit to ground.


    * and yes, because the car door is probably closed most of the time, you could even say "normally", that means that the "normally-closed" door switch spends most of its time "open", as a "normal" thing. It's still called a "normally-closed" switch though, because it's electrically closed when nothing is pushing on it.

    My little baby then became a brother-in-law to dad
    And so he became my uncle though it made me very sad
     
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  14. valde3

    valde3 Senior Member

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    No. See what ChapmanF post. It explains how the system works.
     
  15. Braveslice

    Braveslice Junior Member

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    Hey guys!

    An update: After multiple but harmless noob mistakes, I realized that 12V battery is 98% dead, today I was supposed to get a new one, but the store is closed during weekends (I guess because covid or something like that). Battery is 9 months old, if that is a hint to some direction.

    So it takes a bit more time before I’m able to move forward in testing. Thank you for your patience.

    Cheers
     
  16. sam spade 2

    sam spade 2 Senior Member

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    Do you mean 9 months.......or 9 YEARS ?
    Big difference.
    Of course if the dome light is on all the time the battery will go dead in a couple of days.......or overnight.
    That does NOT necessarily mean that it is now ruined.

    It would be another "rookie mistake" to buy a new battery before you try to charge up the one you have......IF it really is less than a year old.