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2001 Prius HV ECU replacing

Discussion in 'Generation 1 Prius Discussion' started by EddieAtl, Nov 20, 2014.

  1. EddieAtl

    EddieAtl HYBRIDATL

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    Hello,
    I am having a error code PI636 and P3002 on my 2001 Prius. :( it seems that my HV ECU is malfunctioning (fail to communicate properly) :eek: if I replace it.. how can I start initialization so the system can recognize it? do I need any special tools? is there a way to do it manually?
    Thank you guys for any advise (y)
    Eddie
     
  2. Britprius

    Britprius Senior Member

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    As far as I am aware there is no procedure apart from fitting the ECU. The only common failure when opening the HV battery is the safety interlock operation when refitting. After closing the handle the interlock must slide down to complete the operation.

    John (Britprius)
     
  3. EddieAtl

    EddieAtl HYBRIDATL

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    Appreciate the input John!
     
  4. Britprius

    Britprius Senior Member

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    Let us know how things work out.

    John (Britprius)
     
  5. EddieAtl

    EddieAtl HYBRIDATL

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    I wonder if this issue has anything to do with my fuel consumption coming down from averaging 44 to 33 m/g?
     
  6. Britprius

    Britprius Senior Member

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    This is a possibility as the ECU reports the state of charge to the engine and transmission ECU's so that judgments can be made to how much electric assistance the engine is given or even running in electric only.
    If you have not already done so I would also check the state of the 12 volt battery as this can cause many problems. Tyres are another source of heavy fuel use. Have these been changed recently.
    It may be worthwhile to disconnect the HV ECU and re connect "after removing the safety interlock and disconnecting the 12 volt battery" just in case this is a poor contact issue with one of the connectors.

    John (Britprius)
     
  7. EddieAtl

    EddieAtl HYBRIDATL

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    Thank you John for the info. The tires are new LRR the 12 v battery is an optima brand not the original from the dealer and checked out ok. I will try to do what you said and see how it goes. I'll keep you posted, again thank you for the help!
     
  8. ChapmanF

    ChapmanF Senior Member

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    Check the manual, I seem to recall that the HV ECU and the Immobiliser ECU pair with each other, and if you replace either one it triggers a mandatory half-hour wait before you can start the car the first time. That is, key turned to ON and left there for half an hour before turning to START. If you have any doubt about the 12V battery lasting for half an hour of IG ON while the converter isn't charging it, then it's a good idea to connect a battery charger first.

    -Chap
     
  9. EddieAtl

    EddieAtl HYBRIDATL

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    Thanks Chap! Appreciate the help!!
    Will let you know how it goes!
     
  10. EddieAtl

    EddieAtl HYBRIDATL

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    Forgot to mention that don't have the manual, bought the car used. I'll see if i can find one though. Thanks again!
     
  11. Britprius

    Britprius Senior Member

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    What tyres have been fitted? As much detail as you can give and what pressures are you running at. I know this has nothing to do with the ECU problems, but it does have a bearing on your mpg.

    John (Britprius)
     
  12. EddieAtl

    EddieAtl HYBRIDATL

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    Brit, They are defender michelin LRR 175/70/14
    I think i got a good set of tires even though original tires were175/65