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Ignition System Diagnosis

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2002 Saturn SL2, 2002 Saturn SL1, 2002 Saturn SL, 2002 Saturn SC2, and 2002 Saturn SC1. However, it is still accessible from the selected car via links, so may be relevant.
  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. If DTCs P0335, P0340 and P0385 are set, go to next step. If listed DTCs are not set, go to step  4.
  3. Check for short to ground in CKP and CMP ignition feed circuits, or shorted CKP or CMP sensors. Repair as necessary. After repairs, go to step  12.
  4. Check all fuses supplying ignition voltage to each ignition control assembly and fuel injectors. If a fuse is open, repair short to ground in affected circuit and replace fuse. After repairs, go to step  12. If fuses are okay, go to next step.
  5. Using scan tool, check for skewed TP sensor or ECT sensor. Check for skewed or unresponsive MAP sensor. Repair as necessary. After repairs, go to step  12. If sensors are okay, go to next step.
  6. Turn ignition off. Connect fuel pressure gauge. See BASIC FUEL SYSTEM CHECKS . Turn ignition on. Check fuel pressure. If pressure is 41-47 psi (2.9-3.3 kg/cm2 ), go to step  8. If pressure is not as specified, go to next step.
  7. If fuel pressure is indicated, check fuel system. See FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article. If fuel pressure is not indicated, go to FUEL PUMP ELECTRICAL CIRCUIT .
  8. Check for faulty MAF sensor. Replace if necessary. After repairs, go to step  12. If MAF sensor is okay, go to next step.
  9. Check for fouled spark plugs. Replace if necessary. After repairs, go to step  12. If spark plugs are okay, go to next step.
  10. Check for faulty splice connection in battery feed circuit to both ignition control module assemblies. Repair as necessary. After repairs, go to step  12. If circuit is okay, go to next step.
  11. Check for engine mechanical problems. Repair as necessary. After repairs, go to next step. If no problem is found, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article.
  12. Using scan tool, clear DTCs. Attempt to start engine. If engine starts and runs, go to next step. If engine does not start, go to step  2.
  13. Allow engine to reach normal operating temperature. Using scan tool, check for DTCs. If any DTCs set, diagnose DTCs. See appropriate SELF-DIAGNOSTICS article. If no DTCs are set, system is okay.
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