The establishment of the diagnostic code P0183 indicates that the Power Train Control Module (PCM) has observed a voltage signal belonging to the Fuel Temperature Sensor (FTS), higher than expected. In general, this sensor is integrated in the Fuel Composition Sensor (FCS).
The FCS sensor sends information to the PCM, which contains the precise composition of the fuel, as well as an analysis indicating the fuel temperature. When fuel enters through the FCS sensor, check the level of contaminants present. The PCM interprets the fuel temperature as pulse width. The thicker the pulse width signal, the higher the fuel temperature level.
If the fuel temperature is above the ambient temperature, the DTC code P0183 OBD2 is saved.