Ref N REG 2.0L Petrol Turbo Series II.

Please correct me if I am wrong. It is my understanding that 20 seconds after switching off the ignition the engine ECU goes into shutdown mode. During shutdown a short burst of power is sent to the fuel pump then shutdown is complete. On my 2.0 turbo after a period of 20 seconds the fuel pump relay starts oscillating. The only way I can stop it oscillating is by either unpluging it until I next want to use the car of by disconnecting and immediately reconnecting the battery. Then of course I need to reset the clock and re-enter the radio code.