Checking Fuel Pressure Sensor

Checking Fuel Pressure Sensor







NOTE: If diagnostic trouble codes (DTC) for the fuel pressure sensor or atmospheric pressure sensor are stored, these diagnostic trouble codes (DTC) must be fault-traced and remedied first.

HINT: The following method is for checking if the diagnostic trouble code has been caused by a defective fuel pressure sensor. This can be done by comparing if the fuel pressure sensor's signal (readout in the diagnostic tool) is unstable when actual fuel pressure (readout on pressure gauge connected to fuel system's lines) is stable.

- Connect pressure gauge: Fuel pressure gauge

CAUTION: The pressure in the fuel injection system can reach approximately 650 kPa when this diagnostic trouble code (DTC) is stored. Use an adapted manometer.

- Run the engine until it is warm and let it idle.
- A/C off.

Read off relative fuel pressure.

The relative fuel pressure is calculated from the fuel pressure sensor's and the atmospheric pressure sensor's signal (=absolute pressure minus atmospheric pressure).

Check the value on the pressure gauge and the readout value in the diagnostic tool. If the fuel pressure sensor's readout signal is unstable when the actual fuel pressure (readout on pressure gauge connected to fuel system's lines) is stable, this indicates that there is a malfunction in the circuit for the fuel pressure sensor.

Is the fuel pressure sensor OK?

YES: Refer to Checking Components. Checking Components
NO: Refer to Checking Components and Wiring. Checking Components and Wiring