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immobilizer ecu

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Geomiller, Mar 20, 2015.

  1. Geomiller

    Geomiller Junior Member

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    Can anyone tell where the immobilizer ecu is located
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Actually there is no ECU named "immobilizer". However there is an immobilizer system in the Prius.

    The Prius has an transponder key ECU, which perhaps is what you are referring to. If the fob code does not match the codes logged in the ECU then that ECU communicates with the hybrid vehicle ECU and power source control ECU to prevent the car from starting.

    That ECU is located behind the dashboard on the driver's side of the car. Consult techinfo.toyota.com if you need more specific information about how to locate and remove it.
     
  3. valde3

    valde3 Senior Member

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    You can NOT only change key transponder ecu and key if you lost the key. If that’s what you’re thinking.
     
  4. Geomiller

    Geomiller Junior Member

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    my goal is to replace all the immobilizer ecu's and the only one i can't locate is the transponder key ecu.
    I'm still having no luck locating it . any more specific info on location. I have the entire dash removed .
     
  5. Geomiller

    Geomiller Junior Member

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    Thanks to all i have located it
     
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  6. Bm Raja

    Bm Raja New Member

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    Hello!
    I am facing same problem. Can you please tel me where the ECU immobilizer located,?
     
  7. Geomiller

    Geomiller Junior Member

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    it can be found passenger side, be hide the heater
     
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  8. fresno.prius

    fresno.prius Junior Member

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    I am also trying to replace my transponder key ECU. Could someone answer two questions relating to this?
    1 Does someone have instructions on getting to the transponder ECU? I can't seem to find the exact location in the service manual and whether to work from the top of the dash down, or the bottom of the dash up, to get to it
    2 Which is better/easier/cheaper: replacing the transponder ECU with a new one ($280) and programming the existing two keys or replacing transponder ECU with a used one ($30) and programming new keys? I haven't tried programming Prius keys before so not sure what is involved. I have Techstream lite but haven't played much with it other than have it open all four doors on one click of remote.
    Thanks!
     
  9. Figster10

    Figster10 Member

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    Which option ended up being the cheapest or best for you?
     
  10. TOYORICKY

    TOYORICKY New Member

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    Hi I attached a screenshot of the immobilizer, Can you confirm that this is the same one you replaced ?

    I haven't had any luck finding it on the car .
    I only found the red smart key module .
     

    Attached Files:

  11. Codysoshelp

    Codysoshelp New Member

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    Did you find it where is it located and what does it look like? I'm about to loose my mind with this thing
     
  12. John Ginn

    John Ginn New Member

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    What problem did you have that made you decide to change the Immobilzer ECU?

    My Prius had a fuse go out the other day due to the Inverter cooling pump now my car will not sense the key FOB. Toyota tried to reprogram it and it wouldn’t take. I have to insert the FOB into the slot to drive the car. I also have no unlock ability other than the manual key.
     
  13. mr_guy_mann

    mr_guy_mann Senior Member

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    Do you have more than 1 fob? If so then do both have the same problem? Are the fob batteries new?

    I would confirm that the DOME fuse (15 amp) is good (does the dome light work?).

    Then you would need to see what codes are in the smart key ecu ("certification" ecu?).

    The immobilizer refers to the system with the dash slot ("transponder" ecu).

    Posted via the PriusChat mobile app.
     
  14. John Ginn

    John Ginn New Member

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    I have the red car on dash with the key in it and Toyota nor a locksmith could get the smart key to work or unlock the door s.
    Originally the AC/DC inverter pump smoked and blew the AM2. Fuse.


    I just don’t know what else to check
     
  15. mr_guy_mann

    mr_guy_mann Senior Member

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    Which red car symbol - where on the dash is it?

    I assume that the pump and the fuse were replaced. Have you checked the new fuse to be sure it's good?

    If you put the fob in the dash slot and press the power button once, then twice - what happens exactly? Does the clock come on? How about the MFD (radio - A/C display)?

    If you have a SKS Gen2 Prius, there are 16 ecu's that should respond if you use a capable scantool to check for codes. My next step would be to see what systems respond and what codes are present.

    At the top of the Technical Discussion forum is a sticky thread that reviews several scantool apps and devices.

    Posted via the PriusChat mobile app.