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Home >> Oldsmobile >> 2000 >> Intrigue GL >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P1133: Ho2S Insufficient Switching - Sensor 1 >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . After performing OBD system check, go to next step.
  2. Using scan tool, clear DTCs. Reset fuel trim values. Start and operate engine to normal operating temperature. Using scan tool, monitor HO2S voltage for sensor that applies to this DTC. If HO2S voltage is fixed within 351-551 mV, go to step  4. If HO2S voltage is not fixed within 351-551 mV, go to next step.
  3. Visually inspect HO2S for water intrusion, open or short in circuit, inoperative HO2S heater, poor connector terminal contact, exhaust leak (within 12 inches upstream of sensor) or faulty HO2S. Repair as necessary. After repairs, go to step  17. If no problems were found, fault is not present. See DIAGNOSTIC AIDS .
  4. Turn ignition off. Disconnect harness connector to affected HO2S. Using a jumper wire, jumper HO2S low circuit to ground. Jumper HO2S high signal circuit to ground. Turn ignition on, with engine off. Using scan tool, monitor affected HO2S voltage. If voltage reading is 20 mV, go to step  7. If voltage reading is not 20 mV, go to next step.
  5. Turn ignition off. Remove jumper wires from HO2S terminals. Disconnect PCM harness connector containing the affected HO2S high and low circuits. Using a DVOM, check continuity of high and low circuits between HO2S harness connector and PCM harness connector terminals. If resistance on circuit(s) is less than 5 ohms, go to next step. If resistance on circuit(s) is not less than 5 ohms, go to step  9.
  6. Check for proper PCM connector terminal contact. Repair as necessary. After repairs, go to step  17. If terminal contact is okay, go to step  16.
  7. Remove jumpers from HO2S terminals. Turn ignition on, with engine off. Using a test light, connect test light between HO2S heater ignition feed and heater ground circuit harness connector terminals. If test light illuminates, go to next step. If test light does not illuminate, go to step  10.
  8. Turn ignition off. Reconnect HO2S harness connector. Disconnect PCM harness connector containing the affected HO2S low circuit. Using a DVOM, check continuity of low circuit between HO2S harness connector and ground circuit terminals. If resistance is less than 500 ohms, go to step  12. If resistance is not less than 500 ohms, go to step  11.
  9. Repair circuit with a high resistance. After repairs, go to step  17.
  10. Repair HO2S heater ignition or ground circuit. After repairs, go to step  17.
  11. Repair high resistance between HO2S low circuit and PCM ground circuit. After repairs, go to step  17.
  12. Check for exhaust leak upstream of suspect HO2S. Repair as necessary. After repairs, go to step  17. If exhaust leak is not present, go to next step.
  13. Allow engine to cool down to ambient temperature. Using DVOM, check resistance between HO2S low circuit terminal and PCM ground circuit terminal. If resistance is less than 500 ohms, go to step  15. If resistance is not less than 500 ohms, go to next step.
  14. Remove HO2S from exhaust. Clean HO2S mounting threads. Apply anti-seize compound to sensor threads. Install and tighten HO2S to 30 ft. lbs. (41 N.m). Using DVOM, check resistance between HO2S low circuit terminal and PCM ground circuit terminal. If resistance is less than 500 ohms, go to step  17. If resistance is not less than 500 ohms, go to next step.
  15. Replace HO2S sensor. After replacing sensor, go to step  17.
  16. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  17. Using scan tool, clear DTC. Turn ignition off and wait 15 seconds. Start and operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step  2.
  18. Using scan tool, select CAPTURED INFO function. If any undiagnosed DTCs are displayed, go to appropriate DTC test.
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