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Home >> Saturn >> 2003 >> LW200 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Sensors & Switches >> Crankshaft Position Sensor >> Diagnostic Procedures
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Diagnostic Procedures

  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 2.2L SATURN "L" SERIES article.
  2. Attempt to start the engine. Does the engine start and run? If yes, go to next step. If no, go to step  4 .
  3. Turn ignition off. Disconnect the PCM. Measure resistance between the signal circuit and low reference circuit of the CKP sensor with a DVOM. Is the resistance within 500-900 ohms? If yes, problem is intermittent. If no, go to step  11 .
  4. Crank engine. Observe the CMP Resync Counter parameter with a scan tool. Does the CMP Resync Counter increment? If yes go to step  12 . If no, go to next step.
  5. Test the signal circuit for a short to voltage, open, or high resistance. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  6. Test the low reference circuit for a short to voltage, open, high resistance, or CKP sensor circuits shorted together. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  7. Test for an intermittent and for a poor connection at the PCM. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  8. Test for an intermittent and for a poor connection at the CKP sensor. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  9. Remove the CKP sensor. Visually inspect CKP sensor for physical damage, excessive play or looseness, improper installation, foreign material passing between CKP sensor and reluctor wheel, excessive air gap between CKP sensor and reluctor wheel, or electromagnetic interference in the CKP sensor circuits. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  10. Inspect the CKP reluctor wheel for physical damage, excessive end play or looseness, or improper installation. Did you find and correct the condition? If yes, go to step  13 . If no, go to next step.
  11. Replace CKP sensor. After replacement, go to step  13 .
  12. Replace PCM. See appropriate REMOVAL & INSTALLATION article. Perform PCM relearn procedure. See PCM REPROGRAMMING under PROGRAMMING. After repair, go to next step.
  13. Turn OFF the ignition for 30 seconds. Start engine and operate vehicle. Observe the MIL, vehicle performance, and driveability. Does the vehicle operate normally, with no MIL illumination? If yes, system is okay. If no, go to step  2 .
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