Fuel Temperature Sensor: Description and Operation

Fuel Thermosensor:

PURPOSE
Measure fuel temperature and provide ECU with a signal used in calculations for fuel injection system operation, ignition timing, idle speed control, and purge control.

LOCATION
In fuel rail beneath intake manifold.

OPERATION
Thermosensor is a negative temperature coefficient thermistor. This means as temperature increases, resistance decreases. Cold fuel is more dense than warm fuel. To calculate fuel temperature, ECU measures thermosensor resistance via reference voltage fluctuations.

TEMPERATURE / RESISTANCE (K OHMS)

68°F (20°C) / 2.2K - 2.7K
176°F (80°C) / 0.29K - 0.35K