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Thread: E38 DVT fuel composition reset

  1. #1
    Lifetime Member Gregs's Avatar
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    Default E38 DVT fuel composition reset

    Just want to verify that i'm reading this correct, we should only click reset if the ethanol percent is less than 10% but greater than 0%. Here is a pic of the button in the DVT control panel.

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    03 Silverado 5.3 ECSB 4x4 Z71
    Comp Cam 206/212 .515/.522 112 lSA, hardened rods with LS9 springs

    2010 Tahoe VVT AFM 5.3
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  2. #2
    Lifetime Member GMPX's Avatar
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    Yeah I think that was correct (less than 10%), the sensor recalibrates to a non ethanol fuel.
    I no longer monitor the forum, please either post your question or create a support ticket.

  3. #3
    Lifetime Member Gregs's Avatar
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    Quote Originally Posted by GMPX View Post
    Yeah I think that was correct (less than 10%), the sensor recalibrates to a non ethanol fuel.
    Thanks,

    I see there is a toggle button in the tune to specify calculation vs physical sensor. Does anyone know if it's possible to convert to a real sensor and which pins on the PCM I would need to connect to?

    03 Silverado 5.3 ECSB 4x4 Z71
    Comp Cam 206/212 .515/.522 112 lSA, hardened rods with LS9 springs

    2010 Tahoe VVT AFM 5.3
    Stock for now

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    Yes, a pretty common thing to add an actual sensor as the "virtual" sensor kinda-sorta works. GM did it to try and remove the physical sensor cost, but I believe they added it back on later vehicles (don't quote me on this part). On the E38, the signal pin is pin 40 on the black X1 connector (there's a good writeup on g8nation as well). Make sure you change the sensor style to physical, and copy all the FF values over from a factory FF tune.

    I'm in the midst of doing this on my Sonic (E78) so I can run E85 on it.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
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  5. #5
    Lifetime Member Gregs's Avatar
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    Quote Originally Posted by ScarabEpic22 View Post
    Yes, a pretty common thing to add an actual sensor as the "virtual" sensor kinda-sorta works. GM did it to try and remove the physical sensor cost, but I believe they added it back on later vehicles (don't quote me on this part). On the E38, the signal pin is pin 40 on the black X1 connector (there's a good writeup on g8nation as well). Make sure you change the sensor style to physical, and copy all the FF values over from a factory FF tune.

    I'm in the midst of doing this on my Sonic (E78) so I can run E85 on it.
    Thanks for the info, i will checkout the writeup on g8nation. It's too cold to do a conversion in an unheated garage right now. I may end up disabling flex fuel until this spring when it warms up and I can do the conversion to an actual sensor.

    A couple weeks ago I ran the tank nearly dry and filled up with E0 fuel. Reset the fuel composition. I noticed that the reset would set the fuel composition to 3.3% ethanol. As I've been driving around for the last while the number has slowly been trending upward. It's currently at 14% with E0 fuel! I'm going to start doing some poking around online to see if anyone understands the calculated formula that it's using. I suspect the computer's increasing fueling to bring the LTFT's into the 0 to -2 range.

    03 Silverado 5.3 ECSB 4x4 Z71
    Comp Cam 206/212 .515/.522 112 lSA, hardened rods with LS9 springs

    2010 Tahoe VVT AFM 5.3
    Stock for now

  6. #6
    Joe (Moderator) joecar's Avatar
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    The physical sensors are relatively cheap now, about $50 or so.

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