Fuel System Pressure Release: Diamante
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Mitsubishi Outlander, 2003 Mitsubishi Montero Sport, 2003 Mitsubishi Montero, 2003 Mitsubishi Lancer, and 2003 Mitsubishi Galant. However, it is still accessible from the selected car via links, so may be relevant.
Remove the rear seat cushion. Remove the fuel pump/fuel gauge floor cover plate and disconnect the wiring connector at the fuel pump/gauge assembly. See Fig 1. Start the engine and let it run until it stops naturally, turn the ignition off. Re-connect the fuel pump/gauge wiring harness connector. Install the rear seat cushion.