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Home >> Pontiac >> 2001 >> Aztek Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P1189: Engine Oil Pressure Switch Signal Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, observe engine oil pressure parameter in the PCM IPC data list. If engine oil pressure parameter displays OK, problem is intermittent. If engine oil pressure parameter does not display OK, go to next step.
  3. Disconnect engine oil pressure switch harness connector. Connect a fused jumper between engine oil pressure switch harness connector terminal and a good ground. Using scan tool, observe engine oil pressure parameter in the PCM IPC data list. If engine oil pressure parameter displays LOW, go to step  6. If engine oil pressure parameter does not display LOW, go to next step.
  4. Turn ignition off. Check Black/White wire between engine oil pressure switch and PCM for open, high resistance, or short to voltage. Repair as necessary. After repairs, go to step  9. If circuit is okay, go to next step.
  5. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  9. If connections are okay, go to step  8.
  6. Turn ignition off. Check for poor connections at engine oil pressure switch. Repair as necessary. After repairs, go to step  9. If connections are okay, go to next step.
  7. Replace engine oil pressure switch. After replacing switch, go to step  9.
  8. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  9. Turn ignition on, with engine off. Using scan tool, clear DTCs. Operate vehicle within the conditions for running this DTC. See CODE ENABLE CRITERIA . If DTC resets, go to step  2. If DTC does not reset, system is okay.
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