Fuel Rail Temperature Sensor (CNG & LPG)
WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Fuel Rail Temperature (FRT) sensor is integral to compuvalve. FRT sensor is used to calculate fuel density. FRT sensor is supplied a 5-volt reference signal from compuvalve and as temperature of fuel sensor element increases, FRT sensor resistance increases.