1999 Saturn SL2 Automatic, MP6FACTORY OEM SERVICE PROCEDURE

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, command AIR pump relay on and off. If AIR pump turns on and off, go to step  10. If AIR pump does not turn on and off, go to next step.
  3. Turn ignition off. Disconnect AIR pump relay connector. Turn ignition on, with engine off. Using test light connected to ground, probe relay battery supply circuit. If test light is on, go to next step. If test light is off, go to step  16.
  4. Using test light connected to ground, probe relay switched battery feed circuit. If test light is on, go to next step. If test light is off, go to step  17.
  5. Using test light connected to battery voltage, probe relay control circuit. Using scan tool, command AIR 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  9.
  6. Using a fused jumper wire, jumper battery feed circuit to AIR pump feed circuit at relay connector. If AIR pump turns on, go to step  25. If AIR pump does not turn on, go to next step.
  7. Leave fused jumper connected. Disconnect electrical connector from AIR pump. Using test light connected to ground, probe AIR pump harness connector feed circuit. If test light is on, go to next step. If test light is off, go to step  18.
  8. Using test light connected to battery voltage, probe AIR pump harness connector ground circuit. If test light is on, go to step  27. If test light is off, go to step  19.
  9. Turn ignition off. Disconnect ECM harness connector located in engine compartment relay center. Using DVOM, check harness continuity of control circuit. If continuity exists, go to step  29. If continuity does not exist, go to step  20.
  10. Start engine. Disconnect vacuum hose from cutoff valve. Using scan tool, command AIR solenoid valve on. If vacuum is present at cutoff valve, go to step  13. If vacuum is not present at cutoff valve, go to next step.
  11. Disconnect manifold vacuum supply hose at AIR solenoid valve. If manifold vacuum is present at solenoid valve, go to next step. If manifold vacuum is not present at solenoid valve, go to step  21.
  12. Reconnect vacuum supply hose, and disconnect hose to cutoff valve at solenoid valve. Connect the 2 hoses together using suitable coupler. If vacuum is present at cutoff valve, go to step  23. If vacuum is not present at cutoff valve, go to step  22.
  13. Remove cutoff valve. Using a hand held vacuum pump, apply vacuum to valve and attempt to blow through valve. If valve is open, go to next step. If valve is not open, go to step  24.
  14. Disconnect AIR pump outlet hose. Using scan tool, command AIR pump relay on and off. If air is present at AIR pump outlet when pump is running, go to next step. If air is not present at AIR pump outlet when pump is running, go to step  28.
  15. Check for damaged or blocked AIR hoses and pipes between AIR pump and engine. Repair as necessary. After repairs, go to step  31.
  16. Repair battery supply circuit to relay. After repairs, go to step  31.
  17. Repair switched battery feed circuit to relay. After repairs, go to step  31.
  18. Repair AIR pump feed circuit between AIR pump and AIR pump relay. After repairs, go to step  31.
  19. Repair open or high resistance in AIR pump ground circuit. After repairs, go to step  31.
  20. Repair open or high resistance in relay control circuit. After repairs, go to step  31.
  21. Repair vacuum supply hose or plugged vacuum source. After repairs, go to step  31.
  22. Repair vacuum hose to cutoff valve. After repairs, go to step  31.
  23. Replace solenoid valve. After replacing valve, go to step  31.
  24. Replace AIR cutoff valve. After replacing valve, go to step  31.
  25. Check for poor connections and terminal tension at relay harness connector. Repair as necessary. After repairs, go to step  31. If connections and terminals are okay, go to next step.
  26. Replace relay. After replacing relay, go to step  31.
  27. Check for poor connections and terminal tension at AIR pump harness connector. Repair as necessary. After repairs, go to step  31. If connections and terminals are okay, go to next step.
  28. Replace AIR pump. After replacing AIR pump, go to step  31.
  29. Check for poor connections and terminal tension at ECM harness connector. Repair as necessary. After repairs, go to step  31. If connections and terminals are okay, go to next step.
  30. Replace ECM. New ECM must be programmed with theft deterrent module frequency code currently on vehicle. After replacing ECM, go to next step.
  31. Using scan tool, clear DTCs. Turn ignition off for 15 seconds. Start engine and operate vehicle. Check for DTCs. If DTC P0411 is set, repeat step  2. If DTC P0411 is not set, go to next step.
  32. If other DTCs were present during OBD system check and have not been diagnosed, go to applicable DTC. If no other DTCs are present, system is okay.
Factory Service Tools

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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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