Fuel Pressure Sensor/Switch: Service and Repair

Fuel Pressure Sensor G247

The fuel pressure sensor - B - is located in the fuel rail. It measures the current fuel pressure in the high pressure system and delivers a voltage signal to the Engine Control Module (ECM).






Special tools, testers and auxiliary items required

• Engine Bung Set (VAS 6122)

Removing

• Follow the guidelines for a clean working environment when working on the fuel system. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

• Always follow these rules before and during work.

- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.

- Before removing, clean the threaded area around the fuel pressure sensor using a commercially available detergent. Dirt must not enter the bore.

- Open the wire strip - arrows - and remove the connector for the glow plug.






- Set the wire set aside.

• Clean carefully, the cleaner must not enter the connector.

- Dry the fuel pressure sensor.

- Release and disconnect the connector - B - for the fuel pressure sensor.

- Remove the fuel pressure sensor.






- Extract the contamination from the fuel rail bore (threads and sealing surface). Do not use mechanical tools.

- Seal the fuel rail opening with a plug from the engine bung set (VAS 6122).

Installing

Install in reverse order of removal. When doing this note the following:

• The fuel pressure sensor has a biting edge instead of a sealing ring.

• Check for damage to the sealing surfaces and threads for the fuel pressure sensor. If the sensor is OK, is it possible to reuse it.

• Check the sealing surfaces on the fuel rail opening.

• Coat the fuel pressure sensor threads and biting edge with diesel fuel.

- Turn the fuel pressure sensor by hand.

- Tighten the fuel pressure sensor.

- After installing the fuel pressure sensor, allow the engine run a few minutes at a moderate speed and then turn it off in order to bleed the fuel system.

• The high pressure connections must "not" be opened; the fuel system bleeds itself.

- Check the Diagnostic Trouble Code (DTC) memory, and erase it if necessary. Refer to the vehicle diagnostic tester.

- Turn off the ignition.

- Carefully check the entire fuel system for leaks.

- If there are leaks even though the correct tightening specification was used, replace the affected component.

- Perform a road test where the accelerator pedal is pressed all the way down at least one time. Then check the high pressure area again for leaks.

• If there is still air in the fuel system, the engine may switch to emergency mode during the road test. Turn off the engine and erase the DTC memory. Then continue the road test.

- After the road test, check the DTC memory again.

Tightening Specifications