Fuel Pressure Sensor / Fuel Temperature Sensor (Only Vehicles With Demand Controlled Fuel Pumps)

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Fuel Pressure Sensor And Fuel Temperature Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The fuel pressure sensor is combined and consisted of both the fuel pressure sensor and the fuel temperature sensor. The sensor detects the fuel pressure (the absolute pressure) and the temperature of the fuel in the fuel rail.

Fuel pressure sensor

The pressure sensor is a Piezo resistive type resistor, the resistance of which changes with the pressure. Depending on the pressure in the fuel rail, an analog signal of 0-5 V is transmitted. Low pressure results in low voltage, high pressure in high voltage.

The engine control module (ECM) then uses this signal to adjust the pressure in the fuel rail using the fuel pump control module. Also see Fuel pressure regulation (only vehicles with demand controlled fuel pumps) .

The pressure sensor is supplied with 5 V and grounded in the engine control module (ECM). The pressure sensor transmits a signal indicating the fuel pressure to the engine control module (ECM) on a separate cable.

The engine control module (ECM) can diagnose the fuel pressure sensor. Its signals (pressure and temperature) can be read using VIDA.

NOTE:

The absolute pressure is displayed when using VIDA parameter readout to read off the fuel pressure. If there is no pressure at the fuel rail, the atmospheric pressure will be displayed.

HINT: The relative pressure (absolute pressure minus atmospheric pressure) is displayed when reading off the fuel pressure via a manometer connected to the fuel rail.

Fuel temperature sensor

The temperature sensor is an NTC sensor. The sensor is supplied with voltage (signal) from and grounded in the engine control module (ECM).

The resistance in the sensor changes according to the temperature of the fuel. This provides the engine control module (ECM) with a signal of between 0-5 V. Low temperature results in high voltage (high resistance). High temperature results in low voltage (low resistance).

The engine control module (ECM) uses the signal to calculate the volume of the fuel.

The fuel pressure sensor is on the left-hand end of the fuel rail.