Fuel Pump: Description and Operation

The fuel pump motor, located in the fuel tank, is controlled by the fuel pump relay located in the trunk area. Power for the coil side of the fuel pump relay is supplied on circuit A21. This circuit is HOT when the ignition switch is START or RUN position. Power for the A21 circuit is supplied on circuit A1. This circuit is protected by a fusible link located near the auxiliary jumper post on the left toe box.

Ground for the fuel pump relay, coil side, is controlled by the Powertrain Control Module (PCM) on circuit K51. This circuit connects to cavity 51 of the PCM.

Power for the contact side of the relay is supplied on circuit A12. This circuit is HOT at all times and connects to the battery positive terminal through a fusible link.

When the PCM provides a ground path for circuit K51, the contacts in the relay CLOSE connecting circuits A12 and A141. Circuit A141 connects from the fuel pump relay to the fuel pump motor. Ground for the fuel pump motor is supplied on circuit Z1.