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So. Cal. Tech to Diagnose "Transmission Lock Mechanism" Problem?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by arkestra, Mar 20, 2009.

  1. arkestra

    arkestra New Member

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    On several occasions over the last several weeks, I've had a problem starting my 2005 Prius. I won't go into the details, except to say that on two of those occasions, I got a "transmission lock is abnormal" message, which was the subject of a thread last year. (Ideally, I'd link to the thread here, but they won't let me do that because I do not yet have 5 posts. I will try to insert the link in the "trackback" section below. The thread was "Caution: The transmission lock mechanism is abnormal")

    My regular dealership service dept. has been unable to find any problem (even though I brought it there twice with a hybrid system warning light and the red exclamation mark in a triangle light on). They tested the battery yesterday, and said it was fine. (In case it makes a difference -- I saw on one thread that it could -- I'm sure they did not take out the battery for the test.) At least they didn't charge for anything. I went to another dealership, but the service person seemed uninterested in me giving them my business, basically saying they were unlikely to find anything unless they could duplicate the probelm.

    Can anyone recommend a dealership/service place anywhere in Southern California that has a GOOD master technician who could diagnose the problem?

    Thanks for your help

    n
     
    #1 arkestra, Mar 20, 2009
  2. grand total

    grand total Member

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    Despite what the service department said it probably is your 12V battery.
     
    #2 grand total, Mar 20, 2009
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you have a 2005, and the original equipment 12V battery is still installed, I'd suggest that you replace the battery now and be done with it. You'll probably find that the symptom that you described will go away.
     
    #3 Patrick Wong, Mar 20, 2009
  4. brownsnoutuk

    brownsnoutuk Active Member

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    I had the same message on my car yesterday. It was definately 100% the 12v battery.
     
    #4 brownsnoutuk, Mar 20, 2009
  5. TucsonPrius

    TucsonPrius Member

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    As others said, this is a sign that your 12V battery is dying.

    When this happened to me, I picked up a new battery at the Toyota dealership and replaced it myself. Took about 20minutes. If I remember correctly all you need is a 10mm socket with a long (6") extension. The Toyota dealership even took back the old battery for recycling so I didn't have to worry about proper disposal.

    Some people suggest getting an Optima with the belief that is a better battery; I have no idea if they are better or not. I do know that I didn't think it was worth the trouble of getting a conversion kit....

    Thanks,
    Shawn
     
    #5 TucsonPrius, Mar 21, 2009
  6. richard schumacher

    richard schumacher shortbus driver

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    #6 richard schumacher, Mar 22, 2009
  7. keith_w

    keith_w New Member

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    #7 keith_w, Mar 22, 2009
  8. arkestra

    arkestra New Member

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    thanks for all the responses. after another little problem on saturday morning, i went to my regular dealership and received better service with a new service person. the battery was replaced and, although it's only been a little more than 24 hours, so far, so good. thanks again everyone.
     
    #8 arkestra, Mar 22, 2009
  9. zenMachine

    zenMachine Just another Onionhead

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    Just came back from a five-day vacation to find the 12V battery dead. Kinda unexpected since we've left SKS on for longer periods before without problem. (The car has 80K on it already.)

    Anyhow, after doing the classic hatch crawl to jump the battery (the car was parked head-first in the garage) this message came up.

    "Caution: There is a problem with the transmission "P" lock mechanism. Park your car on a flat surface, and fully apply the parking brake."

    Is this the same (or a similar) error message as above? Is it correct to assume that this is only a 12V battery issue?

    The wife has taken the car to work so I can't do the Maintenance Mode battery check yet, but I'm hoping it's no more serious than that and that the 12V battery will be recharged enough so she can make it back home to... fix dinner! :)
     
    #9 zenMachine, Aug 3, 2010
  10. Mike Dimmick

    Mike Dimmick Active Member

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    The message comes up whenever the car has tried to apply the parking pawl, but the position sensor shows that the pawl hasn't fully engaged in the expected time. This can happen for numerous reasons, but of course one is that the battery was too flat, or 12V system voltage too low, to allow the motor to drive the pawl forward quickly enough.

    A DTC should have been recorded by the Transmission Control ECU to allow the problem to be properly diagnosed. However, it's probably C2318 Low Voltage Error (Power Supply Malfunction). This DTC is apparently recorded whenever the car is IG-ON and the battery voltage is 9.3V or less, for at least one second.
     
    #10 Mike Dimmick, Aug 3, 2010
    Dxta likes this.
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes, this is the same error message, and it sounds like your car needs a new 12V battery.
     
    #11 Patrick Wong, Aug 3, 2010
  12. zenMachine

    zenMachine Just another Onionhead

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    Thanks for the confirm, Patrick.

    Seems like the Optima Yellow Top is a favorite for many PC'ers. Is it significantly better than the Toyota one? Any recommendation on where to buy one?
     
    #12 zenMachine, Aug 3, 2010
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Some PC members think so. The following website seems to be a favorite: 12 Volt (12v) Toyota Prius Auxilary Battery for 2004, 2005, 2006, 2007, 2008, 2009 and 2010 with installation kit

    The Toyota battery works well for my purposes, MSRP is $139, and that battery is certainly easier to install because you don't have to replace the battery terminal connectors.
     
    #13 Patrick Wong, Aug 3, 2010
  14. zenMachine

    zenMachine Just another Onionhead

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    #14 zenMachine, Aug 3, 2010
  15. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That's great, let me know if your order is accepted at that price. (Most Toyota dealer parts depts will not ship batteries because they are considered hazardous material.)
     
    #15 Patrick Wong, Aug 3, 2010
  16. Larry Ratso

    Larry Ratso New Member

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    What should I do if the problem with transmission P-lock mechanism warning comes back AFTER I had the dealership replace a weak five year old battery? Don't think the mechanics at the dealership I used were too familiar with this issue.
     
    #16 Larry Ratso, Mar 3, 2018
  17. ChapmanF

    ChapmanF Senior Member

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    Somebody now (the dealer, or you if you have a laptop with Techstream, or a local shop with Toyota experience) should read the trouble codes and freeze frame data from the transmission control ECU, look them up in the repair manual and follow the steps there to determine what the actual problem is. That could also have been done before changing the battery, but you do at least have a new battery now.

    -Chap
     
    #17 ChapmanF, Mar 4, 2018
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