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Home >> GMC >> 2003 >> Jimmy 2D Utility, Part Time, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 26 (Engine Controls - System & Component Testing) >> Fuel Systems >> Fuel Pump Electrical Circuit Diagnosis (3.0L) >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS in SELF-DIAGNOSTICS - 3.0L VUE article.
  2. Turn ignition on, with engine off. Command the fuel pump relay ON and OFF with a scan tool. Does the fuel pump turn ON and OFF? If yes, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article. If no, go to next step.
    3. NOTE: An audible click should be heard.
  3. Command the fuel pump relay ON and OFF with a scan tool. Do you hear a click when you command the fuel pump relay ON and OFF? If yes, go to next step. If no, go to step  9 .
  4. Turn ignition on, with engine off. Does fuel pump operate continuously? If yes, go to next step. If no, go to step  6 .
  5. Turn ignition off. Disconnect fuel pump relay. Turn ignition on, with engine off. Does fuel pump operate continuously? If yes, go to step  20 . If no, go to step  24 .
  6. Is fuel pump fuse open? If yes, go to next step. If no, go to step  10 .
  7. Disconnect the fuel pump harness in-line connector, located near fuel tank. Test the supply voltage circuit of the fuel pump for a grounded circuit. Replace fuel pump fuse, if necessary. Did you find and correct the condition? If yes, go to step  26 . If no, go to next step.
  8. Lower the fuel tank if necessary. Test or inspect fuel tank electrical harness for damage to the harness or grounded fuel pump voltage supply circuit. Replace fuel pump fuse, if necessary. Did you find and correct the condition? If yes, go to step  26 . If no, go to step  17 .
  9. Turn ignition on. Disconnect fuel pump relay. Turn ignition on, with engine off. Probe the fuel pump relay control circuit with a test light connected to ground. Command the fuel pump ON and OFF with a scan tool. Did the test light illuminate? If yes, go to step  18 . If no, go to step  19 .
  10. Turn ignition off. Disconnect fuel pump relay. Turn ignition on, with engine off. Probe the battery positive voltage circuit of the fuel pump relay with test light connected to a good ground. Does test light illuminate? If yes, go to step  12 . If no, go to next step.
  11. Turn ignition off. Disconnect fuel pump fuse. Turn ignition on, with engine off. Probe the battery positive side of the fuel pump fuse with test light connected to a good ground. Does the test light illuminate? If yes, go to step  21 . If no, go to step  22 .
  12. Connect a 10-amp fused jumper wire between the battery positive voltage circuit and the fuel pump supply circuit in the fuel pump relay cavity. Does the fuel pump operate? If yes, go to step  18 . If no, go to next step.
  13. Disconnect the fuel pump harness in-line connector, located near fuel tank. Test the supply voltage circuit of the fuel pump for an open or for high resistance between the fuel pump relay and the in-line connector. Did you find and correct the condition? if yes, go to step  26 . If no, go to next step.
    14. NOTE: Inspect fuel pump ground circuit for being tight, corrosion on terminals, or damage to wiring harness.
  14. Test the ground circuit of the fuel pump for an open or for high resistance between the body pass through connector and the ground. Did you find and correct the condition? If yes, go to step  26 . If no, go to next step.
  15. Inspect for poor connections at the fuel pump in-line connector to the body pass-through connector. Did you find and correct the condition? If yes, go to step  26 . If no, go to next step.
  16. Lower fuel tank. Test or inspect the fuel tank electrical harness for damage to the harness, short to ground or an open circuit. Did you find and correct the condition? If yes, go to step  26 . If no, go to step  23 .
  17. Connect all disconnected components. Install a new fuel pump fuse. Command the fuel pump ON with a scan tool. Is fuel pump fuse open? If yes, go to step  23 . If no, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.
  18. Inspect for poor connections at the fuel pump relay. Did you find and correct the condition? If yes, go to step  26 . If no, go to step  24 .
  19. Inspect for poor connections at the harness of the ECM. Did you find and correct the condition? If yes, go to step  26 . If no, go to step  25 .
  20. Repair supply voltage circuit of the fuel pump for a short to voltage. After repairs, go to step  26 .
  21. Repair battery positive voltage circuit of the fuel pump relay for an open. After repairs, go to step  26 .
  22. Repair battery positive voltage circuit of the fuel pump fuse for an open or a short to ground. After repairs, go to step  26 .
    23. NOTE: Inspect for poor connections at the fuel pump, within the fuel tank, before replacing the fuel pump.
  23. Replace fuel pump relay. After replacing relay, go to step  26 .
  24. Replace fuel pump relay. After replacing relay, go to step  26 .
  25. Replace ECM. See REMOVAL & INSTALLATION article. After replacing ECM, go to next step.
  26. Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step  2 .
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