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Home >> Saturn >> 2002 >> SL >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - Basic Diagnostic Procedures >> No-Start Diagnosis >> No Start - Engine Cranks Okay (2.2L & 2.4L - ALERO, Cavalier, Grand Am & SUNFIRE) >> Fuel Pump Electrical Circuit

Fuel Pump Electrical Circuit

  1. If diagnostic system check has already been performed, go to next step. If diagnostic system check has not been performed, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS in appropriate SELF-DIAGNOSTICS article.
  2. Connect scan tool. Turn ignition on. Using scan tool, command fuel pump relay on and off. If fuel pump turns on and off, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article. If fuel pump does not turn on and off, go to next step.
  3. Using scan tool, command fuel pump relay on and off. If fuel pump relay clicks, go to step  9. If fuel pump relay does not click, go to next step.
  4. Turn ignition off. Disconnect fuel pump relay located in underhood fuse/relay center. Turn ignition on. Using test light connected to ground, probe fuel pump relay control circuit. Using scan tool, command fuel pump relay on and off. If test light turns on and off, go to next step. If test light does not turn on and off, go to step  6.
  5. Connect test light between fuel pump relay control circuit and fuel pump relay ground circuit. Using scan tool, command fuel pump relay on and off. If test light turns on and off, go to step  19. If test light does not turn on and off, go to step  22.
  6. If test light remains illuminated, go to next step. If test light does not illuminate at all, go to step  8.
  7. Test the control circuit of fuel pump relay for a short to voltage. Did you find and correct the condition? If yes, go to step  27. If no, go to step  26.
  8. Test the control circuit of the fuel pump relay for a short to ground or an open. Did you find and correct the condition? If yes, go to step  27. If no, go to step  20.
  9. Turn ignition on, with engine off. If fuel pump operates continuously, go to next step. If fuel pump does not operate continuously, go to step  11.
  10. Turn ignition off. Disconnect fuel pump relay. Turn ignition on, with engine off. If fuel pump operates continuously, go to step  21. If fuel pump does not operate continuously, go to step  25.
  11. Check F/P-INJ fuse (20-amp) located in underhood fuse/relay center. If fuse is open, go to next step. If fuse is okay, go to step  14.
  12. Test the supply voltage circuit of fuel pump for a grounded circuit between fuel pump fuse and fuel pump. Replace fuel pump fuse, if necessary. Did you find and correct the condition? If yes, go to step  27. If no, go to next step.
  13. Install all disconnected electrical components. Install a new fuel pump fuse. Turn fuel pump on with scan tool. Is fuel pump fuse open? If yes, go to step  24. If no, problem is intermittent.
  14. Turn ignition off. Disconnect fuel pump relay, located in underhood fuse/relay center. Turn ignition on, with engine off. Using test light connected to ground, probe fuel pump relay ignition feed circuit at relay cavity. If test light illuminates, go to next step. If test light does not illuminate, go to step  23.
  15. Connect a fused jumper wire between fuel pump relay ignition feed circuit and fuel pump power supply circuit at relay cavities. If fuel pump operates, go to step  19. If fuel pump does not operate, go to next step.
  16. Check fuel pump power supply circuit for open or high resistance between fuel pump relay and rear body harness connector. Repair as necessary. After repairs, go to step  27. If circuit is okay, go to next step.
  17. Check fuel pump ground circuit for open or high resistance between ground and body pass-through harness connector. Repair as necessary. After repairs, go to step  27. If circuit is okay, go to next step.
  18. Check for poor connections at fuel pump. Repair as necessary. After repairs, go to step  27. If connections are okay, go to step  24.
  19. Inspect for poor connections at fuel pump relay. Did you find and correct the condition? If yes, go to step  27. If no, go to step  25.
  20. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  27. If connections are okay, go to step  26.
  21. Repair short to voltage in fuel pump power supply circuit. After repairs, go to step  27.
  22. Repair open in fuel pump relay ground circuit. After repairs, go to step  27.
  23. Repair fuel pump relay ignition feed circuit. After repairs, go to step  27.
  24. Replace fuel pump. After repairs, go to step  27.
  25. Replace fuel pump relay. After repairs, go to step  27.
  26. Replace PCM. Perform PCM relearn procedure. After repairs, go to next step.
  27. Operate system to verify repair. If system operation is okay, testing is complete. If system operation is not okay, go to step  2.
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