https://docs.emtronaustralia.com.au/engine-management/reference/sensor-ratiometric-correction/index.htmlOverview A sensor’s analog output is always proportional (ratiometric) to its supply voltage. The lower the supply voltage, the lower the sensor output voltage. The ECU can correct for this variation in supply voltage and improve sensor performance by applying a ratiometric correction; this is a ratio of the actual sensor supply to the calibrated/ideal sensor supply (5.0V). To do this the ECU must know what supply has been wired to the sensor. There are currently 4 options:Hugoen-us