Fuel Pressure Sensor: Description and Operation

Fuel Pressure Sensor







Overview
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.
The fuel pressure sensor is on the right-hand end of 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. 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 Vehicle Information and Diagnostics Application (VIDA).

NOTE: The absolute pressure is displayed when using Vehicle Information and Diagnostics Application (VIDA) parameter read outs 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.