1. The site is migrating to a new server this week, so there will likely be some downtime during that process. You can follow along here for updates.

OBD2 Power

Discussion in 'Prius v Technical Discussion' started by Air_Boss, May 29, 2023.

  1. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    3,805
    1,025
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Quick question: Is the OBD2 port powered (live) when the car is off (prior to pressing START button, after shutting down with START button, systems not at READY)?

    Situation: On the 2012 v Five, I have a sensor attached to the OBD2 port whose LCD display of engine and systems parameters has recently decided to stay on, powered after the car has been shut down.
     
    #1 Air_Boss, May 29, 2023
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    6,741
    3,903
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Powered up all the time. Some smart devices monitor the voltage level and sleep below 13v. That is not always reliable, so my P10 monitor also watches for rpm and will sleep after a period of minutes without rpm.
     
    #2 rjparker, May 29, 2023
    Tim Jones and Air_Boss like this.
  3. Mendel Leisk

    Mendel Leisk Patron saint of newly poured sidewalks

    Joined:
    Oct 17, 2010
    52,486
    37,082
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Memory saver cables (for maintaining 12 volt when swapping batteries) take advantage of the constant-on 12 volt in the OBD port, have just the 12 volt pins.
     
    #3 Mendel Leisk, May 29, 2023
    Tim Jones and Air_Boss like this.
  4. jzchen

    jzchen Newbie!

    Joined:
    Apr 9, 2012
    3,201
    979
    0
    Location:
    Arcadia, CA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Googling it says pin 16 is 12 V always on.
     
    #4 jzchen, May 29, 2023
    Air_Boss likes this.
  5. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    21,635
    14,073
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    If I remember right, the ScanGauge II had a "hybrid mode" I could select during setup, so it would not go to sleep every time the engine stopped.

    But I set it up a long time ago, so I might not remember right.
     
    #5 ChapmanF, May 29, 2023
    Mendel Leisk and Air_Boss like this.
  6. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    3,805
    1,025
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    It’s a P10 that is staying on. Just changed the 12V battery, whose resting voltage is below 13v. (Didn’t happen with the six year old end of life battery.)
     
    #6 Air_Boss, May 30, 2023
  7. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    6,741
    3,903
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    There are several adjustments. I believe I set the off timer to 180 seconds, verified it did not have a speed offset and set it for one of the protocols as listed in step 10 in pdf.

    IMG_0276.jpeg IMG_0277.jpeg
     

    Attached Files:

    #7 rjparker, May 30, 2023
    Tim Jones likes this.
  8. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    3,805
    1,025
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Thanks. Good thoughts. Perhaps it reset itself when the original 12V aux battery went dead-dead.
     
    #8 Air_Boss, May 30, 2023
  9. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    2,567
    1,100
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    I believe you had it right; it functions while the engine is stopped. However, my ScanGauge II shows phantom fuel consumption when the car is coasting with injectors and ignition off, so the fuel consumption-related data it shows is not credible. For the same reason, the fuel calibration procedure shown in the manual never settles on any one value as it should.
     
    #9 CR94, May 30, 2023
  10. Air_Boss

    Air_Boss Senior Member

    Joined:
    Jun 2, 2012
    3,805
    1,025
    0
    Location:
    New Yawk
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    It is a P12, which somehow reset itself to factory. Once customized, works fine again.
     
    #10 Air_Boss, Jun 1, 2023
    jzchen likes this.
(You must log in or sign up to post here.)
Loading...
Similar Threads - OBD2 Power
  1. Shrug

    Power Struggle?

    Shrug, Sep 29, 2022, in forum: Prius v Technical Discussion
    Replies:
    7
    Views:
    2,588
    bisco
    Mar 29, 2023
  2. mrmriza

    prius as nissan note e-power

    mrmriza, Nov 6, 2021, in forum: Prius v Technical Discussion
    Replies:
    2
    Views:
    4,143
    bisco
    Nov 6, 2021
  3. DS Justice

    Can I get an elevation profile from the onboard static pressure sensor?

    DS Justice, Mar 8, 2018, in forum: Prius v Technical Discussion
    Replies:
    4
    Views:
    5,314
    RobH
    Mar 10, 2018
  4. Bill the Engineer

    Firebrid: The Prius v Powered Hybrid Convertible

    Bill the Engineer, Jul 4, 2017, in forum: Prius v Technical Discussion
    Replies:
    555
    Views:
    265,765
    Bill the Engineer
    Sep 19, 2023
  5. PixelRogue

    Simple software recall turns into weeks of drama ... Power Control Module

    PixelRogue, May 18, 2014, in forum: Prius v Technical Discussion
    Replies:
    7
    Views:
    2,436
    Paradox
    May 18, 2014