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Battery levels and CEL?

Discussion in 'Gen 2 Prius Technical Discussion' started by Rio Kamimura, Sep 23, 2012.

  1. Rio Kamimura

    Rio Kamimura Junior Member

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    2004 Prius
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    Hey guys im new to the prius group. I just bought a prius from a private owner yesterday for 6k$ year 2004 package 9 with 147k miles. Seemed like a good deal so i went for it. The fob key didnt work so today i replaced the battery. The buttons on the key to unlock and lock the car work fine yet the smart key wont detect when im by the car or when i push the car lock button on the door. I tried turning on and off the smart key under the steering wheel and nothing seems to work. It did work once or twice today but after that it hasnt worked.

    Also when i purchased this car he said the check engine light has been on for a while. He took it to the toyota dealer where his friend said it was a cat convertor issue. He told me he replaced the cat convertor with an aftermarket one that cant be read by the toyota prius. Does anyone know how to get that convertor read by the prius?

    Also when i tested for the 12v battery the off levels were around 12.3 and on levels was 13.9 is that considered normal?
     
    #1 Rio Kamimura, Sep 23, 2012
  2. jdcollins5

    jdcollins5 Senior Member

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    2010 Prius
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    III
    1) Welcome and congrats.
    2) Not sure about the Smart Key issue. You may have to take it to a dealer or someone that can test key fobs and have them test the smart key for you.
    3) Since the cat was replaced with an aftermarket one you will not be able to read the cat so the CEL will remain on. Depending on your location you may have problems passing vehicle emissions inspection.
    4) The 12V battery voltages appear normal.
     
    #2 jdcollins5, Sep 24, 2012
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    What this means is that the aftermarket catalytic converter is not working very well so the Prius engine ECU thinks that the cc should be replaced. You might try replacing the air/fuel ratio sensor and the oxygen sensor as the engine ECU depends upon those sensors to assess the performance of the cc. However there is a reasonable chance that a complete repair will require you to replace the cc yet again, with the correct part or at least one which has better performance than the installed part.

    12.3V is low. You might use a battery charger to charge up the battery overnight. Then, let the battery rest for a few hours to dissipate surface charge and see whether the IG-OFF voltage has improved.

    Regarding the Smart fob, if it is intermittent then perhaps there is something wrong with it. If you have a second fob, you might install a new fob battery in that and see if there is any difference.

    If you don't have a second fob then you should purchase one from your local dealer because if you lose your one & only fob it will cost a substantial amount (up to four-digits) to get a new fob recognized by the immobilizer ECU, without a working fob available to the tech doing the work.
     
    #3 Patrick Wong, Sep 24, 2012
  4. Rio Kamimura

    Rio Kamimura Junior Member

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    Okay thanks a lot guys. The CEL was a P0420 code so im going to take it to the dealer tomorrow and see if i can get the warranty for the cat done.

    Also what kind of battery charger do you guys reccomend? Is there a thread on how to charge the battery too?
     
    #4 Rio Kamimura, Sep 24, 2012
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