VW Passat & Audi A4 1990-2000

Relieving Fuel System Pressure


Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well-ventilated area. Do NOT allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

The fuel injection system operates under high pressure. This makes it necessary to first relieve the system of pressure before servicing. The pressurized fuel, when released, may ignite or cause personal injury.

  1. Disconnect the power to the fuel pump by removing the relay or the fuel pump fuse. Check the list on the fuse box lid to be sure. The fuse should be removed to stop the fuel pump from running.
  3. With the engine operating at idle, wait until the engine stalls from fuel starvation.
  5. Switch the ignition OFF and remove the negative battery cable.
  7. Carefully loosen the fuel line on the control pressure regulator or component to be serviced.
  9. Wrap a clean rag around the connection, while loosening, to catch any fuel.
  11. After service is complete, discard the fuel soaked rag in the proper manner and reconnect the negative battery cable, relay or fuses.