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Help reversed polarity on my 2004

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by rick hughes, Nov 3, 2015.

  1. rick hughes

    rick hughes Junior Member

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    I did an engine swap because of excessive oil consumption and locked myself out with the battery disconnected. In trying to jump to the connection under the hood I reversed the polarity. Bad move! I replaced three ECU,s with no help. I have a Toyota Intelligent Tester, plus a full shop manual. Any help would be greatly appreciated . Tell me what info to get and I will do that.
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Start by inspecting the fusible link assembly, which is the 5" long clear/white plastic box within the main relay/fuse box next to the inverter. The 100A DC/DC link is probably destroyed, and in that case you would need to replace the entire fusible link assembly. Also check the 120A MAIN fuse in the 12V battery positive terminal block.

    Then check all other fuses using an ohmmeter to verify continuity. Do not rely upon visual inspection.

    After you have restored power to all electrical circuits, read the DTC and post. It is certainly possible that the inverter has failed (if the DC/DC converter within was destroyed by the botched jumpstart.)

    It would be unusual for an ECU to fail as a result of this, as the power circuit usually is protected with an inline diode.
     
    #2 Patrick Wong, Nov 3, 2015
    Last edited: Nov 3, 2015
    m.wynn likes this.
  3. rick hughes

    rick hughes Junior Member

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  4. rick hughes

    rick hughes Junior Member

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    No DTC's now, Latched the plug on the hybrid battery and reinstalled my old ECU. Master warning light is now out still won't start. Any thoughts?
     
  5. jdcollins5

    jdcollins5 Senior Member

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    What Patrick said.