Fuel Tank Pressure Sensor

The scan tool range is 0-9. Fuel trim cell is dependent upon engine speed and MAF sensor readings. A plot of RPM vs. MAF is divided into 10 cells. Fuel trim cell indicates which cell is currently active.The scan tool displays 0-5 volts or -17.5-7.5 in of H2O Fuel tank pressure is used extensively for EVAP purge control and EVAP system diagnostics.