The Mercedes-Benz S500 is part of the S-class series of luxury sedans. An important component of the S500 is the fuel pump relay, which turns on the fuel pump when the engine is turned on and powers down the engine when the ignition is shut down. The fuel pump relay is located within the inner structure of the vehicle, however, once accessed, it allows owners to tighten or replace the component as needed.
Ensure that the Mercedes-Benz engine is turned off.
Examine the rear compartment area on the passenger's side of the boot area.
Unscrew the bolts of the trim panel with a socket wrench. Lift the panel off and set the component aside. The fuel pump relay will be mounted in the fenderwell, identifiable as a black rectangular block similar in appearance to a wall cell phone charger.