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ECU Question

Discussion in 'Gen 2 Prius Fuel Economy' started by Herb, Jun 24, 2005.

  1. Herb

    Herb New Member

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    Crofton, MD
    I purchased my 2005 Prius used w/ 6000 miles on it. The car was purchased in Louisiana, but I live in Maryland.

    Tomorrow I am taking it in to my local dealer for the 10,000 mile sevice.

    My question is this. Does the Prius have "regional" program versions for the ECU? I am consistently averaging in the mid 50 mpg range, and I worry that the dealer may flash the ECU with a "Mid Atlantic" programming that might negatively affect my gas mileage.

    There are a couple of posters on this forum who also live in the Washington, DC area that report mileage in the low to mid 40 mpg range.

    I would hate to adversely affect my gas mileage if there is programming that - in theory - is designed to "optimize" fuel economy for different regions, but - in reality - does not.

    Am I just paranoid here or might this be a valid concern?

    Herb
     
    #1 Herb, Jun 24, 2005
  2. DanMan32

    DanMan32 Senior Member

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    Tampa Bay, FL
    Nope, no regional differences. I don't think even Canada has a different body ECU even though their lighting is different.

    The reason many have low mileage is because of their driving habits or environment.

    Take me for example. For the last 9 months, the majority of my driving was 40-55MPH, stops at an average of 5-10 miles apart for 48 miles one way. I got upper 50's for MPG.
    Now that I have been seeing this lady in Tampa, I have been doing more high speed highway driving for about 48 miles, supplemented with several short trips under the 5-10minute mark. The short trips usually include trying to cool off a superheated cabin. My weekend MPG is 47, but I recover to 54-55 during the week.

    There have been interim TSB reprogrammings to correct for ICE not starting issues, some had better efficiencies, others worse. The latest did OK as Kyle has posted. It sounds like you may have the latest programming, but then you might have the second to last, which wasn't so good. What month does the door jamb say it was produced? Is there a sticker under the hood indicating a reprogramming?
    Unfortunately, other than a sticker, only hooking up a Toyota scanner will tell what version programming the engine module (ECM) has.
     
    #2 DanMan32, Jun 24, 2005
  3. paprius4030

    paprius4030 My first Prius

    Joined:
    Aug 12, 2004
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    Location:
    York,Pa.
    Vehicle:
    2012 Prius
    Model:
    Two
    Tell the dealer to"Just Change the Oil" and don't touch anything else! The Prius tech's here and at my dealer agree"If it ain't broke, don't fix it"
     
    #3 paprius4030, Jun 24, 2005
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