Fuel Pump

Output signal from ECM or PCM controls relay that operates fuel pump. When ignition is turned on, pump will operate for 2 seconds without ignition switch being turned to crank engine, after which time pump will be de-energized. In addition, if engine stops with ignition on, pump will be de-energized after 2 seconds. Pump operates continuously while ignition switch is set to crank engine, or when engine is running. Supercharged vehicles are equipped with a secondary fuel pump. Both fuel pumps operate under certain conditions.