Fuel Pump Relay: Description and Operation

Right Side Underhood Electrical Center Details:

Fuel Pump Control Circuit Diagram (Typical Operation):

When the ignition key is first turned to the "ON" position, the PCM will energize the fuel pump relay for two seconds. This increases fuel pressure for cranking. If the engine is not running within two seconds, the PCM will shut off the relay and wait until the engine starts. As soon as the engine is cranked, the PCM will energize the relay and power the fuel pump.

NOTE: Once the engine is started, the fuel pump relay is by-passed and a switch in the oil pressure sensor provides power to the fuel pump. The fuel pump relay can be bypassed manually, and the pump operated on demand, by connecting a jumper wire between the correct terminals of the oil pressure sensor connector, or by applying battery power to the fuel pump prime connector.