Start by activating the Ethanol sensor on wired digital input (DINx).
Check real time value for connected ethanol sensor in the RealTime Data tab in MTune.
If 85% and 0.0degree C = no sensor connected. If temperature is 125 degree C, the polarity is wrong, change active level high/low.
Note: If fuel is contaminated, MaxxECU will store an error code.