2002 Mercury Villager BaseFACTORY OEM SERVICE PROCEDURE

Test HC: Fuel Delivery System: Testing

  1. 1) Check System Integrity

    Turn ignition off. Inspect fuel system for leaks, damaged, kinked or cracked hoses. Inspect wiring harness for damage or loose connectors. Ensure battery is fully charged and fuses are okay. If vehicle does not start, ensure vehicle has sufficient fuel in the fuel tank and that Inertia Fuel Shutoff (IFS) switch is not tripped. Repair or replace as necessary. If no faults are found, go to next step.
    2. WARNING: Before performing this test step, release fuel system pressure to reduce risk of injury or fire. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - VILLAGER article.

  2. 2) Check Fuel Pressure
    Turn ignition off. Install fuel pressure gauge in fuel line between fuel filter and fuel rail. Turn ignition on, engine off. Record fuel pressure. Start engine and record fuel pressure. If fuel pressure is about 43 psi (294 kPa) with ignition on, engine off and about 34 psi (234 kPa) with engine running, go to step  40). If fuel pressure is zero, go to next step. If fuel pressure is low, go to step  20). If fuel pressure is high, go to step  30).

  3. 3) Check Voltage To Fuel Pump Relay

    Turn ignition off. Disconnect fuel pump assembly connector at fuel pump. Turn ignition on. Using DVOM, measure voltage between chassis ground and fuel pump harness connector terminal No. 2 (Light Green/Red wire) within 5 seconds of turning ignition on. See Figure. If voltage is more than 10 volts, go to step  9). If voltage is 10 volts or less, go to next step.

  4. 4) Check Power Supply To Fuel Pump Relay

    Turn ignition off. Remove fuel pump relay from left side engine compartment relay block. See Figure. Turn ignition on. Using DVOM, measure voltage between chassis ground and fuel pump relay cavities No. 1 and 3 (Black/Red wires). If voltage is more than 10 volts, leave fuel pump relay removed and go to next step. If voltage is 10 volts or less, check FUEL PUMP fuse (15-amp) and RELAYS fuse (10-amp). If fuse(s) is blown, replace as necessary. If fuse repeatedly blows, repair appropriate power Black/Red wire for short to ground. If fuse(s) is okay, repair open in appropriate Black/Red wire. See WIRING DIAGRAMS article.

  5. 5) Check Fuel Pump Relay

    Connect a jumper wire between battery power to fuel pump relay terminal No. 1. Connect another jumper wire between negative battery terminal and fuel pump relay terminal No. 2. Using DVOM, measure resistance between relay terminals No. 3 and 5. See Figure. Resistance should be less than 5 ohms. Remove jumper wires. Resistance between terminals No. 3 and 5 should now be more than 10 k/ohms. If either resistance is not as specified, replace fuel pump relay and go to step  2). If both resistances are as specified, go to next step.

  6. 6) Check Continuity Of Fuel Pump Relay Circuits To PCM

    Ensure ignition is off. Disconnect PCM harness connector. Inspect connector for damaged pins and repair if necessary. Using DVOM, measure resistance of FPR circuit (Blue/Red wire) between fuel pump relay cavity No. 2 and PCM harness connector terminal No. 11. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Blue/Red wire. See WIRING DIAGRAMS article.

  7. 7) Check For Open To Fuel Pump

    Ensure fuel pump relay is removed and fuel pump assembly connector is disconnected. Using DVOM, measure resistance of Light Green/Red wire between fuel pump harness connector terminal No. 2 and fuel pump relay cavity No. 5. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Light Green/Red wire between fuel pump relay and fuel pump assembly.
    8. NOTE: Ensure IFS switch is not tripped. Reset IFS switch if necessary.

  8. 8) Check For Short(s)
    Ensure fuel pump assembly and PCM are disconnected and fuel pump relay is removed. Using DVOM, measure resistance between chassis ground and fuel pump relay cavity No. 5 (Light Green/Red wire). Using DVOM, measure resistance between fuel pump relay cavity No. 2 (Blue/Red wire) and cavities No. 1 and 3 (Black/Red wires). See Figure. If resistances are more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short to ground or between circuit(s). See WIRING DIAGRAMS article.

  9. 9) Check Fuel Pump Assembly

    Ensure fuel pump module assembly is disconnected. Using DVOM, measure resistance between fuel pump assembly connector terminal No. 3 (Black/White wire) and No. 2 (Light Green/Red wire). See Figure. If resistance is .2-5.0 ohms, go to next step. If resistance is not .2-5.0 ohms, replace fuel pump assembly.

  10. 10) Check Fuel Pump Ground

    Using DVOM, measure resistance between chassis ground and fuel pump assembly harness connector terminal No. 3 (Black/White wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, go to step  13).

  11. 11) Check Inertia Fuel Shutoff Switch

    Disconnect and remove Inertia Fuel Shutoff (IFS) switch. Vigorously shake IFS switch to ensure switch trips. Using DVOM, measure resistance between IFS switch harness connector terminal No. 2 (Black wire) and No. 3 (Black/White wire) with IFS switch "Tripped" and "Set". See IFS SWITCH TESTING  table. See Figure. If resistances are as specified and switch trips when shaken, go to next step. If resistances are not as specified or switch does not trip when shaken, replace IFS switch.

  12. 12) Check IFS Switch Ground

    Using DVOM, measure resistance between chassis ground and IFS harness connector terminal No. 2 (Black wire). If resistance is 5 ohms or more, repair open in Black wire. If resistance is less than 5 ohms, repair open in Black/White wire between IFS switch and fuel pump. See WIRING DIAGRAMS article.
    13. WARNING: Before performing this test step, release fuel system pressure to reduce risk of injury or fire. See FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - VILLAGER article.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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