Flex Fuel sensors

Flex fuel sensors measure the amount of ethanol content in the fuel passing through it. The flex fuel sensor has a pre calibrated signal that is sent from the sensor in a 0-5v voltage indicating which amount of ethanol is present. The FOME ECU has the ability to use this data. The signal circuit carries the ethanol percentage via the frequency signal.

The normal range of operating frequency is between 50-150Hz. The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency between 180Hz and 190Hz indicates that the fuel is contaminated.

In TunerStudio you select which input pin you have used for the signal from the flex fuel sensor. You can view % of content using a gauge in TunerStudio.