Sprinter 3500 L5-2.7L DSL Turbo (2004)
Fuel Temperature Sensor: Description and Operation
DESCRIPTION
The fuel temperature sensor is integrated in the high pressure fuel pump next to the fuel quantity valve. The sensor detects the temperature of the fuel and
supplies that information to the ECM. The sensor ranges from - 40°F (-40°C) to 284°F (140°C). If the engine is cold, the actual value sent will read
ambient temperature. The value rises after the engine has been started.
OPERATION
An negative temperature coefficient (NTC) resistor integrated in the fuel temperature sensor alters it's electrical resistance in line with the fuel
temperature (the resistance drops as the temperature rises). The ECM uses this reading to calculate optimum engine performance under all driving
conditions. If the fuel is to warm, the rail pressure in the system is lowered. The controller quantity of the pressure regulating valve is reduced and the
fuel temperature is lowered.