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Check PCS system warning

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by quasi, Sep 20, 2014.

  1. quasi

    quasi New Member

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    got a "Check PCS system" on MFD with blinking PCS light and yellow triangle lit. when stationary, cruise control says "Radar ready" but once moving it says "Check cruise control system".

    no real work done to car or anything special happened at the time. it was working fine and then one morning when starting we found the warning.

    anyone have any ideas on anything else i can check?

    i've gone through forums and have tried the following so far:
    - changed auxiliary battery (this was low on power)
    - checked PCS button under dash
    - checked onboard diagnostics and its showing a speed that matches the display speed while driving (i assume that means radar sensor is working)
    - have cleaned radar sensor
    - tried resetting ECU/codes: battery unplugged and also car on/off 5 times
    - checked OBD2 codes (have ordered a check J2534 cable but took it to Toyota and they claim no codes although i don't know if i believe them)

    we park on a steepish driveway so reading the other tread about the PCs warning after a spring change, i'm going to check if the front wheel speed sensors are plugged in correctly (although i assume the onboard diagnostics check kind of did that as well since i think it compares speed from the wheel sensors and the radar system)
     
    #1 quasi, Sep 20, 2014
    Last edited: Sep 21, 2014
  2. Abdul sattar

    Abdul sattar New Member

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    Same problam with my car itried many tecnitions but not solve
     
  3. Katie preston

    Katie preston New Member

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    I have had the same issue w my Prius v
    Any resolve?
     
  4. bisco

    bisco cookie crumbler

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    welcome!

    has the dealer been unable to solve it? any trouble codes?
     
  5. Katie preston

    Katie preston New Member

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    No last year i took it in and they read the codes and all came back fine.....it’s just strange that after a year the Check PCS warning light randomingly came on again?
     
  6. bisco

    bisco cookie crumbler

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    sounds like a bug. disconnect the 12v for a few minutes.
     
  7. David Beale

    David Beale Senior Member

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    There is a PCS on/off switch under the dash, just like the TPMS set button. Take a flashlight and put your head on the floor looking up and you can find it. It's labled "PCS". The other switch under there is labled "SET", for the TPMS.

    If your yellow "PCS" light is on solid that switch is turned off. I run all the time this way because I don't want PCS to function. Cruise still works just fine with PCS off (DRCC).
     
  8. Katie preston

    Katie preston New Member

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    I have done that and even when the PCS system is OFF the check PSC warning light comes on?
    Thank you!
     
  9. Katie preston

    Katie preston New Member

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    How do I disconnect the 12v?
     
  10. bisco

    bisco cookie crumbler

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    open the hatch and remove the floor. then remove the triangular floor piece in the right wheel well. you will see the battery down there. loosen the negative connection not and wiggle till it comes off. wait a few minur=tes and reverse process.

    there may be pics in the o/m.
     
  11. Katie preston

    Katie preston New Member

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    Yes thanks for the quick reply i just looked in YouTube looks easy enough but i’ll leave it to my husband:) the battery is original and the car is 8 years old so maybe it’s due for a replacement anyway??
     
    bisco likes this.
  12. bisco

    bisco cookie crumbler

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    very likely. average life is around 5-6 years. more in cold climates and less in hot.
     
    Mendel Leisk likes this.
  13. Katie preston

    Katie preston New Member

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    So i replaced the 12 v battery and the very next day the PCS warning light came on! I am at a loss...........
     
  14. bisco

    bisco cookie crumbler

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    sounds like it's back to the dealer, or someone who can read the codes.

    what is the static voltage of the new 12v?
     
  15. Katie preston

    Katie preston New Member

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    No clue....i will get it checked and keep you posted the dealership is such a rip off! But...
     
  16. Kamil

    Kamil New Member

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    Hello Katie,

    Did you manage to fix the issue?

    I got 2011 Lexus CT200h and have the same behaviour...
     
  17. Cloude1

    Cloude1 Junior Member

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    2010 Prius here. Happening to me now.
     
  18. ilovegirls

    ilovegirls Member

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    I had this happen to me last night. I disconnected the battery and left it overnight. This morning I woke up and reconnected the battery. The "check pcs" was still on.

    I pushed the pcs button on and off around 5 times and nothing.

    I turned off the car on and off around 5 times and still nothing.

    I drive the car down the street and the check "pcs" goes away but a little pcs light is on meaning the pcs system is off.

    I'm not sure what made it go away but that is what I did. Hope this helps.
     
    Mendel Leisk likes this.
  19. Mendel Leisk

    Mendel Leisk Senior Member

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    For anyone else hornswaggled by the acronym:

    PCS equals Pre-Collision System
     
    Raytheeagle likes this.
  20. Raytheeagle

    Raytheeagle Senior Member

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    As long as you don’t get bamboozled we should be fine:p.

    Always working on expanding our vocabulary (y).
     
    RachaelH likes this.