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

Just got water pump changed (under recall) two months ago, now check engine light is on, code P1121

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LadyG, Jul 2, 2015.

  1. LadyG

    LadyG New Member

    Joined:
    Jan 14, 2015
    6
    0
    0
    Vehicle:
    2008 Prius
    Model:
    N/A
    So I've done a little googling on the error code and I'm starting to get angry. Is it possible the dealer did the water pump installation wrong or didn't do it at all? Is that what's throwing the error code?

    I haven't checked the coolant levels yet, can I refill that myself? What kind should I purchase?

    And is the valve something that I can do, my mechanic can do, or do I have to bring it to the dealer? My closest dealer wanted $1,200 to fix my headlights (something that cost me $60 and a couple hours to do after being walked through it by the manual and some tutorials here and online) and over $600 to replace my 12 volt battery (I bought the Optima and did it myself). I really do NOT trust them for anything.

    Also my husband wants to go out this weekend. Probably a 120 mile round trip. Safe? Not safe?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,752
    48,967
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    check your gas cap first.
     
  3. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
    8,383
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    I believe p1121 is the 3 way coolant valve. That seems to be a problem with the valve sticking as the cars get older. There are tutorials that will show you how to replace this valve. The recall pump should not have caused this to fail.

    P1121 - Coolant Control Valve Replacement (with pics) | PriusChat

    It should be safe to drive with the p1121 error, it doesn't cause harm to the car.
     
  4. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    745
    0
    Location:
    Finland
    Vehicle:
    2004 Prius

    But it will affect your heater output and slow down engine warm up. So you should fix it at some point.
     
  5. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,837
    1,828
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    Sometimes P1121 can be caused by air in the coolant loop. The coolant acts as a lubricant for the coolant valve so have the loop filled and bled again.

    JeffD
     
  6. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,470
    8,383
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Unless they did something to the regular radiator coolant......they said they had inverter done, which doesn't really involve touching the radiator.
     
  7. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,199
    6,464
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    1. Start by checking the engine coolant level in the radiator. Remove the large black panel over the radiator for access to the cap.
    2. Use Toyota Super Long Life Coolant to refill. This is the pink-colored liquid.
    3. If the coolant level is OK then the valve may need to be replaced. Ask your mechanic if he can do it. It takes some effort to get air out of the engine coolant loop.
    4. It is not safe for the car to be driven a long distance until you have done #1 above and refilled as needed. If there is a large drop in the coolant level, inspect the engine coolant pump for leakage at the pump bearing. This is evident as a pinkish stain which may deposit on the air conditioner compressor.
    5. Your title indicates a coolant pump was replaced under recall, which most likely would be the inverter/transaxle coolant pump. This is unrelated to the engine coolant system, which is the system causing the P1121 fault code.,