Fuel Pump Control Module (Sentra 2.0L)

When ECM supplies ground signal to fuel pump relay, battery voltage is supplied to Fuel Pump Control Module (FECM) and fuel pump. FECM regulates fuel flow by controlling fuel pump ground circuit. Fuel pump is grounded through either dropping resistor, which drops fuel pump voltage to about 7 volts, or through FECM to ground. Battery voltage is supplied to fuel pump under the following conditions:

• During engine cranking.
• Engine coolant temperature is less than 50°F (10°C).
• Engine is running under heavy-load and high-speed conditions.

Under conditions other than those listed, fuel pump control module limits fuel pump voltage to about 7 volts.