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Diagnostic Procedure (Without Feedback Fuel System)

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. 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, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS in SELF-DIAGNOSTICS - 5.7L CORVETTE article.
  2. Turn ignition ON, with the engine OFF. Command fuel pump relay ON and OFF with a scan tool. Repeat the commands as necessary. Does the fuel pump turn ON and OFF? If yes, go to DIAGNOSTIC AIDS  . If no, go to next step.
  3. Command the fuel pump relay ON and OFF with a scan tool. Do you hear the fuel pump relay click when you command the fuel pump relay ON and OFF? If yes, go to step  9 . If no, go to next step.
  4. Turn ignition OFF. Remove fuel pump relay. See Figure . Turn ignition ON, with the engine OFF. Probe control circuit of the fuel pump relay with a test light that is connected to a good ground. Command the fuel pump relay ON and OFF with a scan tool. Does the test light turn ON and OFF? If yes, go to next step. If no, go to step  6 .
  5. Connect a test light between control circuit of fuel pump relay and the ground circuit of fuel pump relay. Command fuel pump relay ON and OFF with a scan tool. Does the test light turn ON and OFF? If yes, go to step  19 . If no go to step  23 .
  6. Does the test light remain illuminated with each command? If yes, go to next step. If no go to step  8 .
  7. Test control circuit of fuel pump relay for a short to voltage. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  27 .
  8. Test control circuit of fuel pump relay for a short to ground and for an open. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  20 .
  9. Turn ignition ON, with the engine OFF. Does the fuel pump operate continuously? If yes, go to next step. If no, go to step  11 .
  10. Turn ignition OFF. Remove fuel pump relay. Turn ignition ON, with the engine OFF. Does the fuel pump operate continuously? If yes, go to step  22 . If no, go to step  26 .
  11. Inspect the F/PMP fuse. Is the fuse open? If yes, go to next step. If no, go to step  14 .
  12. Test supply voltage circuit of fuel pump, between fuel pump relay and fuel pump for a short to ground. Replace the F/PMP fuse if necessary. Did you find and correct the condition? If yes, go to step  28 . If no, go to next step.
  13. Install all removed electrical components. Install a new F/PMP fuse. Command fuel pump relay ON with a scan tool. Inspect the F/PMP fuse. Is the fuse open? If yes, go to step  21 . If no, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 5.7L CORVETTE article.
  14. Turn ignition OFF. Remove fuel pump relay. Turn ignition ON, with the engine OFF. Probe ignition 1 voltage circuit of fuel pump relay, switch side, with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  24 .
  15. Connect a 20-amp fused jumper wire between ignition 1 voltage circuit of fuel pump relay and supply voltage circuit of fuel pump. Does the fuel pump operate? If yes, go to step  19 . If no, go to next step.
  16. Test supply voltage circuit of fuel pump, between fuel pump relay and fuel pump for an open and for high resistance. Did you find and correct the condition? If yes, go to step  28 . If no, go to next step.
    17. NOTE: Inspect the ground circuit for proper torque, corrosion on the terminals, and damage to the wiring harness.
  17. Test ground circuit of fuel pump for an open and for high resistance. Did you find and correct the condition? If yes, go to step  28 . If no, go to next step.
  18. Test for an intermittent and for a poor connection at the fuel pump connector. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  21 .
  19. Test for an intermittent and for a poor connection at the fuel pump relay. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  26 .
  20. Test for an intermittent and for a poor connection at the harness connector of the PCM. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  27 .
  21. Test for an intermittent and for a poor connection at fuel pump connector within the fuel tank. Did you find and correct the condition? If yes, go to step  28 . If no, go to step  25 .
  22. Repair short to voltage in supply voltage circuit of the fuel pump. After repair is complete, go to step  28 .
  23. Repair open or high resistance in ground circuit of the fuel pump relay. After repair is complete, go to step  28 .
  24. Repair open in ignition 1 voltage circuit of fuel pump relay. After repair is complete, go to step  28 .
  25. Replace the fuel pump. See FUEL SENDER (WITHOUT FEEDBACK FUEL SYSTEM) under FUEL SYSTEMS in REMOVAL & INSTALLATION - CORVETTE article. Replace the F/PMP fuse if necessary. After repair is complete, go to step  28 .
  26. Replace the fuel pump relay. After repair is complete, go to step  28 .
  27. Replace the PCM. See POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - CORVETTE article. After repair is complete, go to step  28 .
  28. 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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