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Home >> Cadillac >> 1998 >> DeVille Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Engine Sensors & Switches >> Engine Controls - System/Component Tests >> Engine Oil Level Sensor Diagnosis
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Engine Oil Level Sensor Diagnosis

  1. If powertrain OBD system check has been performed, go to next step. If powertrain OBD system check has not been performed, perform powertrain OBD system check. See POWERTRAIN OBD SYSTEM CHECK in TESTS W/CODES article.
  2. Ensure engine oil level is at full mark on dipstick. Connect scan tool to data link connector. Turn ignition switch to RUN position. Using scan tool, check engine oil level. If OK is displayed, go to next step. If OK is not displayed, go to step 4).
  3. Start engine and let idle. Increase engine speed to 2300 RPM while monitoring oil level on scan tool. If LOW is displayed, no fault is present at this time. If LOW is not displayed, go to step 7).
  4. Disconnect engine oil level sensor harness connector. Using a fused jumper wire, connect engine oil level sensor harness connector terminals. Observe scan tool display. If OK is not displayed, go to next step. If OK is displayed, go to step 12).
  5. Using a fused jumper wire, connect engine oil level input circuit (Brown wire) to ground. Observe scan tool display. If OK is not displayed, go to next step. If OK is displayed, go to step 10).
  6. Turn ignition switch to LOCK position. Remove fused jumper wire. Disconnect PCM harness connector containing engine oil level input circuit. Measure resistance in engine oil level input circuit (Brown wire) between PCM and engine oil level sensor harness connectors. If resistance is not 5 ohms or less, go to step 9). If resistance is 5 ohms or less, go to step 14).
  7. Disconnect engine oil level sensor harness connector. Turn ignition switch to RUN position. Observe scan tool display. If LOW is not displayed, go to next step. If LOW is displayed, go to step 12).
  8. Turn ignition switch to LOCK position. Disconnect PCM harness connector containing engine oil level input circuit. Measure resistance between ground and engine oil level input circuit (Brown wire) at engine oil level sensor harness connector. If resistance is not 10,000 ohms or greater, go to step 11). If resistance is 10,000 ohms or greater, go to step 14).
  9. Locate and repair open in engine oil level input circuit between PCM and engine oil level sensor.
  10. Locate and repair open in engine oil level ground circuit.
  11. Locate and repair short to ground in engine oil level sensor input circuit.
  12. Check for poor connections at engine oil level sensor. If problem does not exist, go to next step. If problem exist, repair as necessary.
  13. Replace engine oil level sensor.
  14. Replace PCM.
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