Fuel Pump Module
WARNING: This page is about a different car, the 2007 Jeep Patriot and 2007 Jeep Compass. However, it is still accessible from the selected car via links, so may be relevant.
When the ECM senses the ignition switch in the On, Crank or Run mode, battery positive voltage is supplied from the ASD relay and the PDC to the fuel pump relay. The ECM will also ground the fuel pump relay driver at this time, closing the fuel pump relay contacts, completing the fuel pump circuit to chassis ground. If the ECM senses the ignition in the ON position, without a engine crank signal for more than 30 seconds, it will open the fuel pump driver circuit, turning off the fuel pump.
The regulated fuel pump, in On and Crank mode will produce 0.4 to 1.5 bar (6 psi. to 22 psi.). In Run mode the fuel pump will produce at least 2.5 bar (36 psi.) not to exceed 2.9 bar (42 psi.) to maintain constant fuel pressure to the injection pump.