Fuel Pressure Sensor/Switch: Service and Repair

Removing And Installing Fuel Pressure Sensor (High-Pressure Sensor)

Preliminary work

INFORMATION:
- Please observe the following for the V6 -->
- The repair concepts for the V6 are the same as for the V8.
- The special features and component deviations are listed and shown in
- More significant deviations are shown in separate descriptions.
- If no special features are specifically highlighted, the assembly and adjustment instructions for the V8 apply.

1. Pull out the fuse for the fuel pump or disconnect the battery. This prevents the fuel pump from starting when the door is opened.
2. Remove intake-air distributor.

Information

Component overview










Removing high-pressure sensor (rail pressure sensor)

WARNING:
- Toxic substances
- Danger of poisoning or suffocation
- Ventilate the work area well.
- Never ingest or inhale.
- Read specific information on the Hazard Sheet.
- Wear personal protective gear.

WARNING:
- Highly inflammable or explosive materials
- Danger of fire or explosion
- Avoid contact with hot parts or sources of ignition.
- Use suction to remove ignitable vapors.
- Attach warning sign in a clearly visible position.

NOTE:
- Dirt on injection system components (intake manifold injection and direct fuel injection system)
- Material damage
- Rough-running engine
- Bad exhaust emissions

WARNING:
- Leaking fuel supply lines
- Emerging fuel
- Risk of fire
- Perform leak test.

INFORMATION:
- Do not bend high-pressure lines. Always remove the high-pressure distribution pipe and other fuel-supply components in the high-pressure area completely. Check that the connection points are not damaged and are perfectly clean and make sure there is no thread damage. Fit union nuts on all connection points by hand before screwing in screws or bolts. Remove dirt on the conical/ball joints. Check connection points for leaks following fitting.
- The ignition must be switched off when working on the fuel system.
- Absorb any escaping fuel using a suitable binding material or a cloth.
- Cloths which have absorbed fuel must be disposed of according to the applicable national laws.
- The fuel system must be depressurized before starting work on it.
- Only work on the fuel system in well-ventilated rooms.
- Any seals which have been removed must always be replaced.







1. Pull off cable plug for high-pressure sensor. -2-
2. Place a cloth around the high pressure sensor. Relieve fuel pressure at fuel distributor pipe (rail) by slowly opening the high pressure sensor using a ring wrench.
3. Remove high pressure sensor. Visually check the thread and sealing ball to make sure they are not damaged.

Installing high-pressure sensor (rail pressure sensor)

INFORMATION: The tightening specifications for the basic engine are stored centrally.

1. Visually check the thread and sealing ball on the high-pressure sensor to make sure they are not damaged.
2. Visually check the threaded bore and sealing cone on the high pressure distributor pipe (rail) to make sure they are not damaged.
3. As in the leak test, blow fuel residues out of the high-pressure distributor pipe by blowing helium through the opening in the high-pressure sensor.
4. Fit the high-pressure sensor. -2-
4.1. Carefully screw the high-pressure sensor by hand into the thread of the fuel distributor pipe. Check that it screws in easily.







4.2. Tighten the high-pressure sensor.

5. Connect cable plug to the high-pressure sensor. -2-
6. Check high-pressure distributor pipe for leaks.

Subsequent work

1. Fit the fuse for the fuel pump or connect the battery.
2. Fit intake-air distributor.
3. Fill and bleed the fuel high-pressure system.