P3102 on 2008

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by MichaelB126, Jul 6, 2026 at 11:30 PM.

  1. MichaelB126

    MichaelB126 Junior Member

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    Hey Folks.
    I've scanned the forum for my code and have gathered it can be a bunch of things.
    Here's what I've done recently changed fuel injector, had one sputtering. Changed plugs and coil packs.
    Had the battery and alternator tested at parts store, both are good.

    No other codes came back using Dr Prius.
    Used multi meter to check the voltage, was low at 5 volts. Charged to 13 and drove next day for 50 miles (one stop with engine off for an hour) and on way home I got the infotainment warning to park on level ground and use parking brake. Charged again then went to parts store to check battery and alternator.
    I saw in a post there are 7 sub codes w 3102.
    Anything else I can check?
    Any guidance on a good scanner thats not $500?
     
    #1 MichaelB126, Jul 6, 2026 at 11:30 PM
  2. PriusCamper

    PriusCamper Senior Member

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    Car Scanner (Elm) app

    But until you got a solid 13v (14.1v in ready mode) from a fresh charged battery chasing codes is a waste of time.
     
    #2 PriusCamper, Jul 7, 2026 at 1:28 AM
  3. pasadena_commut

    pasadena_commut Senior Member

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    I wouldn't trust a battery that had been discharged to that voltage. It might charge up to something reasonable, but it is probably heavily sulfated.
     
    #3 pasadena_commut, Jul 7, 2026 at 1:54 PM
  4. bisco

    bisco cookie crumbler

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    get a free 12v load test at most auto parts stores
     
    #4 bisco, Jul 7, 2026 at 2:03 PM
  5. bisco

    bisco cookie crumbler

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    #5 bisco, Jul 7, 2026 at 2:05 PM
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