1. Attachments are working again! Check out this thread for more details and to report any other bugs.

'p' lock malfunction

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Mareno Rathell, Jan 3, 2016.

  1. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    "There is a problem with the transmission "P" lock mechanism Park your your car on a flat surface and fully apply the parking brake." with the red triangle

    I've done a ton of google searches on this issue with no luck finding a resolution. I was hoping you guys may of heard of a real solution to this issue.

    This message and red triangle is a constant on my 2007 Prius from the moment you turn the car on to the point of shutting it off.

    I'm able to override the message on the screen temporarily by pressing the INFO button on the steering wheel to be able to access other screen functions.

    It's not the 12v battery. I've replaced it twice. load tested both batteries. benched charged them before installing. cleaned the terminals, clean the negative cable and replaced the bolt for the negative cable that bolts to the body and cleaned the threads in the hole of the body.

    I've also tested both batteries using the "turn the headlights on and off three times" method with both new batteries passing.

    The car has only failed to start once for my wife and I'm not 100% convinced her incident was related.

    Any new news on this issue? As anyone with this issue that didn't have to do with the battery successfully resolve their issue?

    I've heard of the brake pedal switch fix and the three relay fix behind the HV battery but they never returned to the forum to say it definitely resolved their issue.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i think you'll need to have the codes read.
     
  3. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    The CEL is not on and when I used a traditional OTC scanner no codes were found, but I'm assuming you mean some deeper Toyota scanning tool.
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    yes, either a dealer (probably a hundred bucks or so) or if you have an old laptop, you can buy a mini vci on ebay for $25. with toyota tech stream diagnostics.
     
  5. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Yes those codes are Hybrid Codes that a OTC will not report.

    If you have a DVM check the battery voltage on the front jump points before starting the car first thing in the AM. Then push the ready button twice with NO BRAKE applied then your in ignition and full load on the 12 volt. Measure the jump points again.
    Then make the car READY and measure the jumps again for charging voltage.

    Report those 3 tests here.
     
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    1. You need to retrieve the DTC. Use Mini VCI.

    2. After you have the DTC, if C2310 has been logged, study this thread to determine whether it is applicable.
    Red Triangle was intermittent, now constant | PriusChat
     
  7. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    Where do you guys get the Toyota software to use with the Mini VCI? I'm assuming there is some cost friendly software available.
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Mini VCI is supposed to be shipped with cloned Toyota Techstream software on a little disc. In addition, the software is floating around on the web.
     
  9. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    Great, I just order one off of Ebay.

    Thanks
     
  10. goldfinger

    goldfinger Active Member

    Joined:
    Mar 12, 2012
    535
    402
    0
    Location:
    Buffalo
    Vehicle:
    2016 Prius
    Model:
    Three
  11. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    Thanks goldfinger, this definitely seems to mirror my issue.

    Let's start off with the assumption/fact that I'm not too smart....I can follow along most of the diagram but I can't find the relay and fuse you referenced. Is that the F15 for the fuse?



     
    bisco likes this.
  12. goldfinger

    goldfinger Active Member

    Joined:
    Mar 12, 2012
    535
    402
    0
    Location:
    Buffalo
    Vehicle:
    2016 Prius
    Model:
    Three
    Everything you need is here, you just have to look for it. I often use Google to search this site as it works better than the built in engine. Here's a picture and a net trick for towing from dogfriend. The two fuses and relay involved are labeled P CON. With car off you should cycle these out and back in again to assure clean connections. If you can energize the relay measure its contact resistance. It should be in the mohms or 0 resistance as seen by a regular multimeter. If you're sure your 12v battery is good then you probably have moisture in the park actuator's connector.

     
  13. Mareno Rathell

    Mareno Rathell Junior Member

    Joined:
    Aug 13, 2012
    29
    3
    0
    Vehicle:
    2006 Prius
    I'm sorry I had a temporary brain freeze when I posted the earlier post about the diagram. I did find the relay and fuse. We own two Prius, one is a 2005 and the other is a 2007. So both fall under Gen 2.

    I switched the relay from the 2005 to the 2007 but the issue continued and the relay from the bad prius didn't transfer to the good prius when I switched the relays.

    I read all of the threads you referenced but I couldn't tell if you attempted to fix the moisture in the park actuator's connector. Did you?

    Also I get the P Lock message only when i come to a stop. It pops up on the screen just a hair before the car completely stops rolling.

    I've tried to see if I could make the message appear by lifting my foot completely off of the brake, rolling for a foot or two and then pushing on the brake pedal would initiate it but it didn't. It seems as though I must pass a certain speed and then come to a complete stop for it to trigger.

    I was attempting to see if it was in anyway tied to the brakelight switch but I think that was ruled out.
     
  14. goldfinger

    goldfinger Active Member

    Joined:
    Mar 12, 2012
    535
    402
    0
    Location:
    Buffalo
    Vehicle:
    2016 Prius
    Model:
    Three
    My p lock occurs when the weather gets wet. Aside checking the relay and fuses I've made no attempt to fix as my car drives, inspection isn't till march, and I hope to buy a new car next year. If I did attempt to fix I would buy a used shift actuator on eBay and have my local garage put it on.
     
  15. Jon o.

    Jon o. New Member

    Joined:
    Nov 2, 2017
    1
    1
    0
    Location:
    Venice, California
    Vehicle:
    2006 Prius
    Model:
    II
    Just had the same problem with my 2006, was intermittent for a week then car just died with all panel lights on. Bought a new 12v battery, didn't help. Had no choice but to have it towed to Toyota where they replaced the parking shift actuator for $1200. My GUESS is that this is one of those electrical components that doesn't age well and it gets flakey (judging by all the intermittent problems noted on this forum). Higher voltage might help but I would think only temporarily. Wish I had asked for the old part, I'll bet there's corrosion and stuff going on inside it. BTW, I live by the beach.
     
    Mendel Leisk likes this.
  16. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    That's a frustrating amount of $'s. :mad:
     
  17. robandjeanne

    robandjeanne Junior Member

    Joined:
    Apr 14, 2007
    12
    1
    0
    12 volt battery was dead, so I charged my 2007 Prius through the terminal under the fuse box cover provided for jump starting. Afterwards I get the "There is a problem with the transmission "P" lock mechanism Park your your car on a flat surface and fully apply the parking brake." with the red triangle. Also after the fact, I read you're only supposed to trickle charge through that terminal. Since I was charging at maybe 15 amps initially I was very worried that I blew some fuse. However after hours of charging the charge current fell to below 3 amps which seemed normal. I followed this procedure to start. I released the parking brake started the Prius and left it idle for awhile, after several minutes it shut off indicating the Prius sensed full charge on the 12 volt battery. So far so good. What might have gotten blown by chaging through the starting terminal?
     
  18. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    745
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    Nothing. You can charge the battery through jump start terminal. There’s a (relatively) thick cable from that to the battery through high current fuse so no problem using it to charge the 12V battery. Prius 12V battery itself shouldn’t be charged faster than 4A and you should only use smart charger so it’s not overcharged.
     
  19. Quixrhyno

    Quixrhyno Junior Member

    Joined:
    Jun 24, 2014
    2
    1
    0
    Vehicle:
    2007 Prius
    Model:
    II
    After 3 months trying everything suggested in these posts I decided to replace every ECU I can get to and BRAVO!!! The 1st one fixed it. The Transmission ECU under the AC unit on the passenger side. Oh man, I’m a happy camper now!
     
  20. ericbecky

    ericbecky Hybrid Battery Hero

    Joined:
    Mar 12, 2004
    4,365
    3,209
    1
    Location:
    Madison, Wisconsin
    Vehicle:
    2005 Prius
    Model:
    Two
    Thanks for sharing this. If possible, periodically check back and let us know if the replacement is still keeping the problem away.

    Congrats on your fix.