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

Smog check fail - OBDII Monitors Not Ready

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by quack724, Jul 21, 2020.

  1. quack724

    quack724 Junior Member

    Joined:
    Jul 21, 2020
    3
    0
    0
    Location:
    94568
    Vehicle:
    2010 Prius
    Model:
    IV
    Hi ,

    I have 2010 Prius that failed for Smog check today. I believe everything passed except the "OBDII Monitors Not ready." See attached photo for details.

    Just over two weeks ago, we had the car serviced for the JOV engine recall where they performed a software update and oil change.

    And just before that, our 12V battery died and I replaced the 12V battery myself.

    So at a minimum, I think the 12V battery replacement is the root cause of the "Not ready"?

    I've been reading other threads and the 3rd party Smog test shop I went to suggested driving the car as normal for about 30 miles or so? But then I read other general articles where they seem to have very specific sequence of steps (I cannot link because I am new).

    I have to pay for each smog check and at the same time, I don't want to buy an OBDII device to check the readiness so I just wanted to know if driving the car as normal for about 100 miles should get the car to be in "ready" status?

    Thank you in advance !

    IMG_2480 (2).jpg
     
    #1 quack724, Jul 21, 2020
  2. AzusaPrius

    AzusaPrius Senior Member

    Joined:
    May 27, 2020
    2,069
    868
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    IV
    Yes put some miles on it like 100-200
    It will be ready then.

    Also you should only go to pass or dont pay smog stations.
    Even then if it is not ready they should not be charging you anything.
    You paid someone already then go back to them after the miles you are doing to get it ready for smog.

    The recall and battery replacement reset the computer so it needs to be driven a good amount to see if any faults show up.
     
    #2 AzusaPrius, Jul 22, 2020
    Bbonez, pjksr02 and quack724 like this.
  3. pjksr02

    pjksr02 Active Member

    Joined:
    Nov 2, 2009
    532
    225
    2
    Location:
    Connecticut
    Vehicle:
    2010 Prius
    Model:
    III
    That seems like an odd not-ready, especially if the catalyst monitor completed and passed.

    Check out the drive pattern below (idle 9 minutes and drive for 2--this may be for older Prius years). Maybe Autozone will read your readiness monitors for free, like they look at check-engine codes.

    Maybe the sensor is on its way out--how many miles on the car?

    Toyota Drive Cycle OBDII Readiness Monitors - A Star Smog - Antioch Smog Check
     
    #3 pjksr02, Jul 22, 2020
    Last edited: Jul 22, 2020
    quack724 likes this.
  4. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    I remember the last smog check I got on our old 2010 that I had pulled the 12 volt lead prior to going to the smog shop:whistle:.

    Had a 40 mile run to get to the shop and all the monitors were ready:).

    You could always try @Joele3 's shop in San Ramon for a smog. Helps a local member too;).

    And he's done a lot in the space of Prii (engine swaps, oil catch cans, multiple generations), so a good one to chat with(y).
     
    #4 Raytheeagle, Jul 22, 2020
    Last edited: Jul 22, 2020
    bisco and quack724 like this.
  5. quack724

    quack724 Junior Member

    Joined:
    Jul 21, 2020
    3
    0
    0
    Location:
    94568
    Vehicle:
    2010 Prius
    Model:
    IV




    The car has just over 144K miles.
     
    #5 quack724, Jul 22, 2020
  6. Mayank Jain

    Mayank Jain Member

    Joined:
    Feb 20, 2018
    99
    70
    1
    Location:
    Cupertino, CA
    Vehicle:
    2012 Prius
    Model:
    Plug-in Advanced
    I just went through this yesterday.
    After covid-19 lockdown, I started my car to find a dead battery. Replaced it with a new one.
    Then for DMV registration, smog check failed - OBD-2 not ready (same as above).
    The mechanic said to drive 100+ miles. I drove on local streets & highway to give the Prius computer exposure to all sort of road conditions.
    SMOG check passed yesterday after driving 105 miles.

    I hope this helps someone in future.
     
    #6 Mayank Jain, Aug 27, 2020
    bisco likes this.
  7. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,557
    10,324
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    How many miles have been driven since these events?
     
    #7 fuzzy1, Aug 27, 2020
  8. quack724

    quack724 Junior Member

    Joined:
    Jul 21, 2020
    3
    0
    0
    Location:
    94568
    Vehicle:
    2010 Prius
    Model:
    IV
    My apologies. I meant to update this thread earlier. We drove about 300 miles since the 12V replaced and first smog check failure. On the 2nd try, our smog check passed. I think I may have been able to bring it back sooner than 300 miles but I had time before our due date and I didn't want to risk a 2nd smog check failure again.
     
    #8 quack724, Aug 27, 2020
  9. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,049
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i can't believe disconnecting the 12v erases all the emissions data...
     
    #9 bisco, Aug 27, 2020
  10. better call Saul

    better call Saul Junior Member

    Joined:
    Dec 22, 2018
    2
    0
    0
    Location:
    Portland
    Vehicle:
    2010 Prius
    Model:
    Three
    Have you tried replacing your gas cap with an OEM gas cap?
     
    #10 better call Saul, Jun 20, 2024
(You must log in or sign up to post here.)