Fuel Temperature Sensor is NTC thermister which voltage gets low if the temperature comes to be high. It is installed in fuel supplying line. It senses the temperature of fuel supplied to high pressure pump. Fuel temperature is limited (engine power is limited) to keep fuel temperature from reaching at 80℃. This limit is to protect fuel line such as high pressure pump and injectors from damages due to rapid deterioration by vapor-lock phenomenon which can occur at high temperature or destruction of oil membrane.

P0183 is set when the voltage above 4.912V - maximum voltage of FTS output - is detected for more than 2.0 sec.. This code is due to 1)open or short to battery in FTS signal circuit or 2)open in ground circuit.