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05 Gen 2 Incessant P- lock issue

Discussion in 'Gen 2 Prius Main Forum' started by Jerry G., Aug 28, 2023.

  1. Jerry G.

    Jerry G. Junior Member

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    Hi Prius Gurus,
    One of my refurbish projects has me stumped with intermittent P lock error. Hybrid battery, Battery ECU and sensing harness has been replaced, cells tested for HV leaks and balanced. Car has 235k on odo. This is what has been done so far to try and fix P-lock problem:

    1) Brand new 12v AGM battery
    2) Fixed the Combo display (new caps)
    3) Checked plug to Shift actuator motor
    4) Replaced Transmission ECU with known good unit.
    5) Tried the wire jumper bypass from Blue wire on fuse box connector to P lock 7.5a fuse.

    what is the likelyhood that the shift actuator is actually bad? Ive never had this issue on 8+ prius rebuilds.
    Thank you in advance for any advice or insight.
     
  2. PriusCamper

    PriusCamper Senior Member

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    Usually the shifter springs fail but not the shifter/actuator... What are the current error codes and subcodes?
     
  3. Tombukt2

    Tombukt2 Senior Member

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    I've never had a problem with one of these and I don't know four or five of these cars so I'm imagining this is inside the transmission and this is what releases the parking paw? So is there a workaround to just get rid of the parking paw all together and use the parking brake? So when the springs go bad these are the springs that the parking solenoid is pushing against to knock it out of gear and so the springs break and the default is to be locked in park? Is there access to this thing from outside of the transmission?
     
  4. Tombukt2

    Tombukt2 Senior Member

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    So running the jumper wire that blue wire is coming on with ignition or is it trying to hold the parking paw solenoid in or out at all times? So if that doesn't work I would think that parking solenoid actuator whatever it is must be bad You can't make it work direct wired?
     
  5. Jerry G.

    Jerry G. Junior Member

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    Hi thanks for the replies. So my TecStream program crashes intermittently and I havent been able to pull any sub codes. Ill try again though.

    I read somewhere that if the computer sees less than 12vdc at the shift motor it throws the code. Ive heard of connection issues at the fusebox causing this condition also.
    The last time this happened was I had cleared the triangle and was driving it. The P-lock error came up randomly while driving. I wasnt aware of the spring breaking. Is that in the transmission or the Shift control motor module??
    I have a shift module from another Prius I could swap out. I guess thats my next step.
     
  6. mr_guy_mann

    mr_guy_mann Senior Member

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    What codes? Could be lots of things, without some kind of guidance you (we) are blindly guessing.

    I think the spring reference was about the shifter on the dashboard. The detent springs can sometimes break and cause problems with functionality.

    Posted via the PriusChat mobile app.
     
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  7. Tombukt2

    Tombukt2 Senior Member

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    I was hoping to hear that about the springs I have an '04 here that looks like coffee or something something sticky and sugar it's smells and like and what have you got into the mechanical linkage and now if you put it in drive it won't go back to the middle It put it in any position it stays there doesn't return to the detent or to the center or whatever it does like my '09 does all the time so I clicked the plastic cover off the front of that thing with the knob off full that off and could see the gooey gunk in there and I just use a spray bottle of water and a paper towel or two folded right underneath the mechanism squirt squirt squirt squirt squirt hot water was in the spread zep spray bottle I'm using. And that hot water melted all that nastiness it rolled out onto the paper towel because the plastic panels are off underneath etc with the key button and all that in them. Caught all that hit it with a little dry spray lube now no matter what I do with that joystick it acts like a joystick supposed to. Maybe if that transmission lever sticks in any of the positions it might could activate this p lock??. I guess I have a transmission at one of these days I'm going to bust it open and have a look in there I hate to do it because it's a good one and see what this parking solenoid or parking Paul which must be electronically operated looks like operates like what have you I haven't seen a breakdown on the computer here with the parts and what have you pictures etc But for some of y'all it seems like this is a thing that happens pretty regular that's wild I would have to come up with a way to disable that thing permanently and just use my parking brake forever roll it right up against the parking curb every time I park that would certainly make parking a lot easier to me too funny.