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how to fix busted eb1 blue wire pin

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by swimyouidiot, Oct 23, 2021.

  1. swimyouidiot

    swimyouidiot New Member

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    Working on my 2006. Has 299,612 miles. Reached battery failure not long ago, and with help of a more talented buddy, recently replaced the hybrid battery (with salvage battery, seems to read good power). Dashboard still lit up, however, so looking for additional problems. Buddy has read codes and says they are confusing. First problem now is that it will not shift into drive or reverse, only goes from park to neutral and nothing else.

    Found the EB1 wire harness junction, and found the pin connecting one of the blue wires (pin 9, I think - "RZ1"?) corroded and busted. What does that pin/wire do and how do you fix it? I've looked at the wiring diagram manual, but am not smart enough to figure it out.

    PXL_20211023_182939335.jpg
     
  2. ChapmanF

    ChapmanF Senior Member

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    Look in Shift Control System, EB1 pin 9 has a blue wire and brings battery power to the transmission control ECU and the indicator LED on the Park button. (Not sure where you saw "RZ1".)

    This is one of those search tasks where if you are signed in to TIS using the online EWD it is super easy—you just point at connector EB1 and click on pin 9 and the whole related circuit gets highlighted.

    I have always found it tends to be those pins that have power 24/7 like that where the worst corrosion happens. Something about the constant, year-in/year-out voltage gradient there accelerating the process.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    If you can wrestle it out of there, determine pin style and find replacement pins you should be able to repair. Might be simplest to cut it back a few inches (or wherever access is easy), crimp some matching gauge wire to the new pin (away from the car), and then just crimp or solder the two cut ends of the wire (at the car).
     
  4. swimyouidiot

    swimyouidiot New Member

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    Thanks so much. I'll see what I can do with that. Certainly sounds like the failure of something that brings battery power to the transmission control ECU could lead to this problem (only shifting into neutral).

    Here's where I got the "RZ1" - not that I really know what it means or how it connects or if it is relevant. From page 251 of the Wiring Diagram Manual:

    upload_2021-10-24_14-6-20.png

    Thanks again!
     

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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Could you temporarily jumper that bad pin, run a wire from the back of one connector to the other, see if it clears anything up?
     
  6. ChapmanF

    ChapmanF Senior Member

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    I do see RZ1 there, and it is a wire that is blue, but not one that goes through EB1 ....