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Home >> Cadillac >> 1998 >> Eldorado Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P1189 - Engine Oil Pressure Switch Circuit >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
  2. Warm engine to normal operating temperature. After warming up engine, turn engine off for at least 30 seconds. Turn ignition on, engine off. Ensure engine was not cranked. Using scan tool, check engine oil pressure. If scan tool indicates that oil pressure is low, fault is not present. If scan tool does not indicate that oil pressure is low, go to next step.
  3. Disconnect oil pressure sensor connector. If scan tool indicates that oil pressure is low, go to step 6). If scan tool does not indicate that oil pressure is low, go to next step.
  4. Using scan tool, record fluid life index. Turn ignition off. Wait 30 seconds then disconnect PCM harness connector C2. Check resistance between ground and PCM harness connector C2 terminal No. 57. If resistance reading is 10,000 ohms or less, go to next step. If resistance reading is not 10,000 ohms or less, go to step 7).
  5. Repair short to ground in oil pressure switch circuit.
  6. Replace oil pressure switch.
  7. Replace PCM. Program replacement PCM using required equipment.
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