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Ran a scan of my Prius

Discussion in 'Gen 3 Prius Technical Discussion' started by Silver2010, Jul 14, 2010.

  1. Silver2010

    Silver2010 New Member

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    Location:
    Sugar Land, TX
    Vehicle:
    2010 Prius
    Model:
    III
    Used my HP Tuner to run a scan of my Prius. Interesting that it only turns about 1400 rpm at 60 mph. Seems fairly low for a small car. My previous Camry and Maxima turned over 2000 at 60 mph. Engine temp. runs in the 190s. It was about 93* ambient during the scan. It has no tach or temperature gauge that I can find so I had no idea. In traffic the engine is off more than I expected. On deceleration it turns off at 35 mph and stays off until the battery needs charging or you start accelerating again. Of course we can feel it come on during acceleration. I assume it will scan about anything the diagnostic port will offer.
     
    #1 Silver2010, Jul 14, 2010
  2. austingreen

    austingreen Senior Member

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    Your car has an electronic CVT and you were in overdrive. The software will choose an engine speed based on the power requirements. There is electric motor generator Mg1 that will spin to provide the proper gear ratio. Mg1 can resist the engine and generate electricity and feed this to the motor turning the wheels, Mg2, or store it in the battery. The faster it spins the easier the gear. It can also reverse direction and provide torque and consume electricity. Think of this as overdrive. If Mg1 is stationary you can think of it as the motor driving the gears directly and this will be around 2000 rpm at 60 mph.

    The prius will keep the engine on at any speed over 45, otherwise it can turn it off depending on power requirements. The battery can provide a burst of about 36 hp to Mg2.

    The following thread talks about the mode that you were in when you read the engine rpm.

    http://priuschat.com/forums/gen-iii...l-mode-third-gen-prius-what-do-we-know-2.html
     
    #2 austingreen, Jul 14, 2010
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  3. JThayer

    JThayer Cubic Zirconium Member

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    IV
    You may find it interesting to look at the correspondence of engine RPM, MG1 RPM and MG2 RPM under different speeds and loads (MG2 will always be in proportion to the speed, by the way...)

    I don't know about the rest of you, but I find the engineering of the PSD fascinatingly elegant.:cool:

    You can get the codes for the MG1 and MG2 RPM from a spreadsheet that can be found on this thread: Scan Gauge II
     
    #3 JThayer, Jul 15, 2010
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  4. Silver2010

    Silver2010 New Member

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    Location:
    Sugar Land, TX
    Vehicle:
    2010 Prius
    Model:
    III
    Interesting guys and thanks for the info. I'll have to go read up on this system. I really have no idea how it works other than what you just told me. It is an amazing little car.

    I use my HP Tuner that I use to tune my 08 Corvette but just found it interesting to hook it up to my Prius just to see what I could scan.
     
    #4 Silver2010, Jul 15, 2010
  5. tedjohnson

    tedjohnson Member

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    Prime Premium
    I don't know about the rest of you, but I find the engineering of the PSD fascinatingly elegant.:cool:


    Yes A great engineering feat. An electromechanical differential that replaces a transmission. Wonderful design !!! I wonder what it would have been like if they were not trying to duplicate the noise and drivability of a regular CVT so people would not get scared away from buying it.
     
    #5 tedjohnson, Jul 18, 2010
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