Right Hand Drive

PURPOSE
The relay mounted in the Power Distribution Center supplies battery voltage to fuel pump and oxygen sensor heater element when energized by Powertrain Control Module (PCM).

OPERATION
The PCM energizes fuel pump relay by supplying relay ground, when ignition switch is in START or RUN position and PCM is receiving a reference signal from distributor.

When the PCM does not receive reference signal from ignition system, (indicating engine is not running), then the PCM interrupts relay ground circuit and no voltage is supplied to fuel pump, ignition coil, or oxygen sensor heater element.

The PCM controls fuel pump relay and Auto Shutdown (ASD) relay simultaneously, through same ground circuit.

CIRCUIT OPERATION
When the ignition switch is in either the START or RUN positions, it connects circuit A1 from fuse 6 in the Power Distribution Center (PDC) to circuit A21. Circuit A21 supplies battery voltage to the coil side of the fuel pump relay The Powertrain Control Module (PCM) provides ground for the relay on circuit K51. Circuit K51 connects to cavity 51 of the PCM.

When the PCM grounds the fuel pump relay, contacts inside the relay close and connect circuit A14 from fuse 14 in the PDC to circuit A141. Circuit A141 connects to circuit A241. Circuit A241 supplies voltage to the fuel pump motor (part of the in-tank fuel pump module).