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Rules for cleanliness > < Safety precautions when working on fuel supply system

Leon Mk2

Releasing pressure in high-pressure area
Releasing pressure in high-pressure area
  WARNING
The injection system is sub-divided into a high pressure system (max. approx. 120 bar) and a low pressure system (approx. 6 bar).
Prior to opening the high-pressure area, e.g. when removing the high-pressure pump, fuel rail, injectors, a fuel line, or the fuel pressure sender -G247-, the fuel pressure in the high-pressure area must be reduced to a residual pressure of approx. 6 bar. The appropriate procedure is described as follows.
   
–  Disconnect the connector of the fuel pressure regulating valve -N276--arrow-.
–  Let the engine idle for approx. 10 seconds.
  Note
t  If the connector of the fuel pressure regulating valve -N276- is disconnected while the engine is idling, the pressure in the high-pressure system drops to approx. 6 bar.
t  Once the pressure has been reduced, the high-pressure system must be opened, as the fuel pressure may increase again due to heating.
–  Switch ignition OFF.
  WARNING
The fuel piping is under pressure. Wear eye protection and protective clothing to avoid eye injuries and skin contact. Before opening the high-pressure section, wrap a cloth around the connection.
–  Place a clean cloth around the connection, and open it carefully to eliminate the residual pressure of approx. 6 bar overpressure. Catch the escaping fuel.
–  Call up the event memory of the engine controller to complete the work. Delete any errors that may have occurred by disconnecting the connector.
  Note
If the fault memory was cleared, the readiness code must be generated → Vehicle diagnostic tester„Guided functions“.
  N20-10283

Rules for cleanliness > < Safety precautions when working on fuel supply system