Fuel pump relay function - GF54.15-P-4105-02L
WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.
Shown on model 140
The fuel pump relay (K27) is switched by a ground signal from the control unit at terminal 86. If the contact is closed, the fuel pump (M3) is connected to terminal 30 (B+) via terminal 87. Circuit 30 is protected by a 30 A fuse.
With models 129, 140, 202, 208, the fuse is attached to the relay.
On vehicles with two fuel pumps, the pumps are connected in parallel.