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Home >> Jeep >> 1998 >> Wrangler SE, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Engine Performance >> Self-Diagnostic Tests >> Test NS-5A: Checking Fuel Pump

Test NS-5A: Checking Fuel Pump

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For component location and wiring diagram, see WIRING DIAGRAMS article.
  1. Using scan tool, stop fuel system actuation. On AB body, go to next step. On all other bodies, actuate fuel pump relay. Feel fuel pump relay. If fuel pump relay does not pulsate, perform TEST TC-101A: FUEL PUMP (SYSTEM) RELAY CONTROL CIRCUIT . If fuel pump relay pulsates, go to next step.
  2. Turn ignition off. Remove fuel pump relay. Substitute a known-good fuel pump relay and attempt to start engine. If engine starts, replace original fuel pump relay and perform TEST VER-1A: NO START VERIFICATION . If engine does not start, go to next step.
  3. Turn ignition off. Remove fuel pump relay. Inspect fuel pump relay connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-1A: NO START VERIFICATION . If connector and terminals are okay, go to next step.
  4. Turn ignition on. Using scan tool in voltmeter mode, check voltage on fuel pump relay connector, fused B+ circuit (Orange/Black wire on AB body; Red/White wire on AN, BE/BR, DN and TJ bodies; Dark Green/Black wire on XJ and ZJ bodies). If voltage is 10 volts or less, repair open fused B+ circuit and perform TEST VER-1A: NO START VERIFICATION . If voltage is more than 10 volts, reinstall original relay and go to next step.
  5. Disconnect fuel pump connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-1A: NO START VERIFICATION . If connector and terminals are okay, go to next step.
    NOTE: Ensure fuel pump connector has clean and tight connections.
  6. Turn ignition on. Using scan tool, actuate fuel system. On AB body, go to next step. On all other bodies, use an external voltmeter to check voltage on fuel pump relay output circuit (Dark Green/Black wire on BE/BR bodies; Dark Green/White wire on all other bodies) between fuel pump relay and PCM. If voltage is 10 volts or less, repair open fuel pump relay output circuit and perform TEST VER-1A: NO START VERIFICATION . If voltage is more than 10 volts, go to step 8)  .
  7. Connect a 12-volt test light to fuel pump relay connector, fuel pump relay output circuit (Dark Green/White wire). If test light does not come on brightly, repair open fuel pump relay output circuit and perform TEST VER-1A: NO START VERIFICATION . Of test light comes on brightly, go to next step.
    WARNING: Fuel system may be under pressure. Release fuel pressure before opening system for testing or component replacement. See FUEL PRESSURE RELEASE .
  8. Using scan tool, stop fuel system actuation. Using an external ohmmeter, check resistance between ground and fuel pump connector, fuel pump ground circuit (Black wire). If resistance is 5 ohms or more, repair open fuel pump ground circuit and perform TEST VER-1A: NO START VERIFICATION . If resistance is less than 5 ohms, replace fuel pump and perform TEST VER-1A: NO START VERIFICATION .
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