Fuel Pump Electrical Circuit

When the key is first turned ON, the PCM energizes the fuel pump relay for two seconds to build up the fuel pressure quickly. If the engine is not started within two seconds, the PCM shuts the fuel pump OFF and waits until the engine is cranked. When the engine is cranked and the RPM signal has been detected by the PCM, the PCM supplies 12 volts to the fuel pump relay to energize the electric in-tank fuel pump. An inoperative fuel pump relay can result in long cranking times, particularly if the engine is cold. An inoperative fuel pump would cause a no start condition. A fuel pump which does not provide enough pressure can result in poor performance.