Fuel Pressure Sensor/Switch: Service and Repair

Fuel Pressure Sensor G247

The fuel pressure sensor (rail pressure sensor) is located inside the fuel rail. It measures the actual fuel pressure inside fuel rail sends a voltage signal to the diesel direct fuel injection (Engine Control Module).

If the sensor malfunctions, the pressure is controlled via an ECM characteristic map. The maximum engine speed is limited to approximately 3000 RPM in emergency mode.

Removing


Follow the guidelines when working on the fuel system. Refer to => [ Safety Precautions ] Safety Precautions.

Follow the guidelines for clean working conditions. Refer to => [ Clean Working Conditions ] Clean Working Conditions.

Always follow these instructions before and during work.

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

- Clean the threaded area around the sensor with, for example, a commercially available detergent, before removing. Dirt must never get into the bore in the fuel rail.

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

- Dry the fuel pressure sensor.

- Disconnect the connector from the fuel pressure sensor.

- Remove the fuel pressure sensor.

- Suction any dirt out of the bore in the rail, the threads and the sealing surface. Do not use mechanical tools.

• Seal the bore in the rail immediately with a suitable plug to prevent dirt from entering.

Installing

• Check the fuel pressure sensor sealing surface and threads for damage.

• Check the sealing surface on the bore in the rail.

• The threads on the fuel pressure sensor are coated with an anti-friction coating. The threads must therefore be free of oil and grease.

- Tighten the fuel pressure sensor hand tight.

- Then, tighten the sensor to specification, see - item 14 - in the => [ Fuel System Component Overview ] Fuel System Component Overview

- After installing, allow the engine to run at a moderate speed for a few minutes and then turn it off.

- Check fuel system for leaks.

- Check the Diagnostic Trouble Code (DTC) memory.

- Perform a road test fully pressing the accelerator pedal at least one time. Then, check the high pressure area for leaks again.

- Recheck the DTC memory, refer to the vehicle diagnostic tester.