High Side Fuel Pressure, Releasing

High Side Fuel Pressure, Releasing

The fuel injection system is divided into a high pressure side (maximum approximately 120 bar) and a low pressure side approximately 6 bar).

Before opening the high pressure side, the fuel pressure must be reduced to a residual pressure of approximately 6 bar. This is the case, for example, when removing the following components:

• High pressure pump

• Fuel rail

• Fuel injectors,

• Fuel pipes

• Fuel pressure regulator valve

• Fuel metering valve 2

For the procedure, refer to "Guided Functions" in the vehicle diagnostic tester.

This reduces the pressure to approximately 6 bar.

The fuel lines are under pressure.

Danger of personal injury to eyes and skin.

Wear protective goggles and protective clothing in order to avoid injury and contact with the skin. Wrap a cloth around the connection before removing a fuel hose. Open the connection carefully and release the pressure.

- Place a clean cloth around the connection point and carefully open, in order to release the residual pressure of approximately 6 bar. Leaking fuel must be absorbed.

- Check the Engine Control Module (ECM) Diagnostic Trouble Code (DTC) memory after completing the procedure. Erase all DTC entries, which may have been produced when the connectors were disconnected.

• Generate a readiness code if the DTC memory was erased. Refer to "Guided Functions" in the vehicle diagnostic tester.