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Request help on decodes for MG1 / MG2 rpm

Discussion in 'Gen 2 Prius Technical Discussion' started by Dan., Aug 31, 2009.

  1. Dan.

    Dan. MPG Centurion

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    Below are the results of poking around with a ScanGauge tool to try to find the MG1 / MG2 rpm data on the 07E2 ECU. I've found the data, I just need to figure out the decodes.
    OK... So I was working on battery gauges as I follow Dan's PHEV Enginer.us conversion. I finally decided to circle back around and get MG1 / MG2 rpm. Good news is I found the data stream, bad news is I don't know the decodes (field width and multiplier/divider). So here's what I have:

    This is a pseudo XGauge since I'm looking at 12 bytes of data instead of 2. The RXD field is invalid since it grabs 192 bits starting at bit 0:

    TXD: 07E2 21C3
    RXF: 0561 16C3 0000
    RXD: 00C0
    MTH: 0001 0001 0000
    Data while in Park: 07EA102761C33FFF0FA00000
    Data in light force charge: 07EA102761C3400111D00000


    TXD: 07E2 21C4
    RXF: 0561 16C4 0000
    RXD: 00C0
    MTH: 0001 0001 0000
    Data while in Park: 07EA102761C4004000600000
    Data in light force charge: 07EA102761C4000092710000

    I suspect some signing (likely 2's complement) but without a set of known good numbers, its gonna be hard to decode. So for PID 21C3, if I look at the whole highlighted DWORD and ignore the first nibble, that gives me -61k at idle, and 70k under load (sounds fishy). Moving onto the 21C4 pid, looking at the low WORD of the DWORD, I read 108 at idle, and -28k at load. I think there is a divide by 10 or something in here for sure.

    I'd be interested in your thoughts.​

    11011011
     
    #1 Dan., Aug 31, 2009
  2. JimboK

    JimboK One owner, low mileage

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    Is it possible to set up an X-gauge to do a calculation? If so, then you can calculate the two from vehicle speed and engine speed:

    • MG2 rpm =~road speed in mph x 57
    • MG1 rpm =(3.6 x engine rpm) -(2.6 x MG2 rpm)
    Or maybe at least knowing these relationships will allow you to map the codes to known values of RPM and MPH. Then again, you might be ahead of me and already know these ratios.
     
    #2 JimboK, Aug 31, 2009
  3. Dan.

    Dan. MPG Centurion

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    I've got another thread on it and looks like the German Prius Pilots may have found the MTH function. Stay tuned.

    11011011
     
    #3 Dan., Aug 31, 2009
  4. ken1784

    ken1784 SuperMID designer

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    I have done using the same math as above.

    Ken@Japan

    [​IMG]

    [​IMG]

    [​IMG]
     
    #4 ken1784, Sep 1, 2009
  5. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Interesting challenge....

    From the red highlighted numbers, I think the last 4 digits could be the RPM. The first 4 digits may be for the sign.

    MG1:
    0FA0 = 4,000 MG1 RPM (ICE at 1,111 RPM?)
    11D0 = 4,560 MG1 RPM (ICE at 1,267 RPM?)

    MG2
    0060 = 96 MG2 RPM (can't be moving in park)
    9271 = 37,489 MG2 RPM (can't be!)
     
    #5 usbseawolf2000, Sep 1, 2009
  6. Dan.

    Dan. MPG Centurion

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    I'm hearing that they may be tourque numbers, but I'm trying to get a handle on mulit-frame can responses.

    11011011
     
    #6 Dan., Sep 1, 2009
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