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How do you manually disengage the park pawl on a XW20 transaxle?

Discussion in 'Gen 2 Prius Technical Discussion' started by electric_sheep, May 1, 2021.

  1. electric_sheep

    electric_sheep New Member

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    I have a Gen2 (XW20) Prius transaxle I want to use for an EV conversion project. The park pawl seems to be engaged, and I'd like to disable it so that I can spin the MotorGenerators.

    I have removed the housing of the little 12V motor that actuates the park pawl as demonstrated in this video
    and I'm spinning the cycloid gear around by hand as she does, but I'm not really sure what I'm doing.

    Is it a case of rotating it around and around until something clicks? I've tried spinning it as far as it wants to turn in either direction, but it hasn't unlocked free rotation of the driveshafts.

    Alternatively, if I reassemble the little motor, is there some combination of pins on the connector that I can energize to get it to unlock electrically?
     
  2. electric_sheep

    electric_sheep New Member

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    Nvm, you just need to spin it all the way counter clockwise until it makes a click sound I think.
     
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  3. justlee

    justlee Junior Member

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    Did you figure it out? It looks like spinning the motor moves the gear behind in and out with a cam or threads thus locking or unlocking the transmission? She called the mechanism a cyclonic gear and it appears to move the lock gear a couple of teeth as it goes in and out. I'm assuming that the meshed gear is what locks the transmission and it looks like if you left out the motor rotor and gear that the transmission would wouldn't have park? Very clever.
     
  4. T1 Terry

    T1 Terry Active Member

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    I've tried lots of ideas on how to get the park pawl disengaged on my '06 gen 2 after I destroyed the traction battery. I can get the dash to light up, but that's about it. Does anyone know if it's possible to remove the cover for the park pawl driver while the transmission is still in the car?
    I need to get the car out of our back patio carport so I can put it on a trailer and take it to the local Toyota dealer so he can do a report regarding the traction battery for the insurance company. There is no way of getting a skid tray truck or car trailer up to where the car is situated, so I have to be able to roll it back down driveway and between the house and garage to get it to some where it can be loaded onto a trailer.

    T1 Terry
     
  5. dolj

    dolj Senior Member

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    Can you get it on a towing dolly?
     
  6. T1 Terry

    T1 Terry Active Member

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    No, not until I can get it backwards down the drive beside the house and then the 90* left between the house and garage. There is no way to get in front of the car with anything that could hold the wheels, except maybe those wheely devices they use for getting race cars in and out of the pit garage ..... but I doubt they'd handle the trip back down the driveway over the pavers, not terribly flat and the little wheels don't like that.

    I guess I'll have to jack it up, take the left hand wheel off and the dust guard and see if I can get to the park pawl motor ...... it would be so much easier if there was a pin out for the park pawl motor plug so I could power it to disengage the park pawl .....

    T1 Terry
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    What’s ended up happening in at least one such scenario reported here in past: a tow truck was called and the car was dragged backwards, to a location where front was accessible. Not pretty, kinda costly, but works.
     
  8. T1 Terry

    T1 Terry Active Member

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    Can't do that in this case, the tow truck wouldn't fit between the house and garage and still make the 90* left turn to get up behind the Prius. If I could get a flat tray up there then I'd do the bread board under the tyres trick mentioned here some where ... still might do that and use the other Prius to drag it out.
    If it wasn't for the fact I have to present the car as it was after the volunteer fire brigade empties a 9kg dry powered extinguisher over the traction battery, I just pull it out and put the traction battery from my high mileage ex taxi Prius in and drive it out that way.

    Actually .... maybe I can lay the other traction battery on the floor or the back seat and just transfer the wiring across .... that might work ....

    T1 Terry
     
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  9. Skibob

    Skibob Senior Member

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    How did your battery catch fire?
     
  10. dolj

    dolj Senior Member

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    Search recent threads by the poster to get the scoop.
     
  11. T1 Terry

    T1 Terry Active Member

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    I was trying to find out what voltage the Prius considered 100% SOC reading off the scan gauge. What I didn't do and should have done, was measure each module voltage to make sure they were even. The voltage in a few of the modules must have gone very high resulting in the electrolyte boiling and creating a flammable gas. The metal battery cover actually bowed up from the explosion that preceded the fire. I actually put the fire out twice, once through the fan outlet near the back door and the second time while I was unbolting things to get to the battery and by then I had the top of the battery cover exposed and the flames came out from under that metal cover, so I emptied the rest of my little car sized dry powder extinguisher.

    T1 Terry