Fuel Pump Relay: Description and Operation

FUEL PUMP CONTROL

The ECM activates the main relay (2/32) when the ignition is switched ON. The fuel pump relay (2/23) is activated simultaneously for one second to enable the pump (6/31) to develop pressure.

As the engine is turned by the starter motor, the RPM sensor (7/25) and CMP sensor (7/21) deliver engine speed and crankshaft position signals to the ECM, which activates the fuel pump relay. The fuel pump functions continuously when the engine operates.