Procedures

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 sensor

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

This reduces the pressure to approximately 6 bar.

Fuel lines are pressurized! Always wear protective eyewear and protective clothing to prevent injuries and fuel from coming in contact with your skin. Before opening the high pressure side, place a cloth around the connection.

- Place a clean cloth around the connection point and carefully open 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.

• If the DTC memory was erased, generate a readiness code, refer to "Guided Functions" in the vehicle diagnostic tester.