Fuel Pressure Sensor/Switch: Testing and Inspection

Fuel Pressure Sensor, Checking





Special tools, testers and auxiliary items required

• Assembly tool (T10118)

• Socket wrench insert 27 mm (VAS 5301/7)

• Pressure sensor tester (VAS 6394/1)

• Adapter (VAS 6394/2)

• Test adapter (VAS 5570)

• Torque Wrench (V.A.G 1331)

• Vehicle diagnostic, testing, and information system (VAS 5051B)

Work procedure:

- Remove engine cover => [ Engine Cover, Removing and Installing ] Engine Cover, Removing and Installing.

- Remove the Fuel Pressure Sensor (G247) => [ Fuel Pressure Sensor, Removing and Installing ] Service and Repair.

- Coat the adapter (VAS 6294/2) sealing point with clean engine oil and install it in the fuel rail. Tightening Specifications 22 Nm.





- Remove the locking bolt - 2 - and install the fuel pressure sensor (G247) in the pressure sensor tester (VAS 6394/1). Tightening specifications 22 Nm.





- Connect the pressure sensor tester (VAS 6394/1) pressure line to the adapter (VAS 6394/2).

- Connect the fuel pressure sensor and its electrical connector with the test instrument adapter (VAS 5570)





- Switch the pressure sensor tester (VAS 6394/1) on by pressing the button - A - briefly.





• Holding the button - A - for 2 seconds switches on the illumination for 20 seconds.

• If the pressure sensor tester (VAS 6394/1) does not display 0 bar, set it back to zero => operating instructions.

- Connect the tester to the diagnostic connector.

- Switch on ignition.

- Press the following buttons in the tester screen one after another.

Fahrzeug-Eigendiagnose

Eigendiagnose >

01 - Motorelektronik >

011 - Messwerte >

- Select the measured value block 1 4 0 and confirm with the Q button.

Display field 3 shows the fuel pressure actual value as measured by the fuel pressure sensor (G247).

- Start engine.

- Compare the pressure displayed by the pressure sensor tester (VAS 6394/1) with the actual value displayed on the vehicle tester.

• The pressures may have a maximum difference of 5 bar.

- If the difference is greater than 5 bar, replace the fuel pressure sensor (G247).

CAUTION!
The pressure sensor tester (VAS 6394) is under high fuel pressure. Disconnect the connector from the fuel pressure sensor (G247) when the engine is running. This reduces the pressure to approximately 6 bar. Switch off ignition. Place a rag around the fuel pressure sensor (G247), then carefully loosen the to release the remaining pressure.

- Repeat the test with the new fuel pressure sensor (G247) and compare both measured values.

If the measured value do not match again:

- Perform a wiring test.