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Home >> Isuzu >> 2000 >> Hombre S, 2.2 4, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Trouble Code Identification >> DTC P0133: O2S Slow Response Sensor 1 >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic II (OBD-II) system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK in SELF-DIAGNOSTICS - INTRODUCTION article. After performing OBD-II system check, go to next step.
  2. Install Tech 2 scan tool. Start engine. Ensure engine is at normal operating temperature. Operate vehicle within the conditions required for setting this DTC. Using scan tool, monitor the following:
    • LEAN/RICH AVG. (249 ms).
    • RICH/LEAN AVG. (249 ms).
    • RICH/LEAN RATIO (greater than 3.75).
    • LEAN/RICH RATIO (less than 0.4).

    If scan tool values are about as specified, go to next step. If scan tool values are not as specified, go to step  4.

  3. If other DTCs are present, diagnose affected DTC(s). If no other DTCs are present, go to step  5.
  4. Replace oxygen sensor. Determine cause of sensor contamination, otherwise new sensor will be damaged. Possible causes are:
    • Use of silicon sealant
    • Engine coolant leaking into combustion chamber
    • Excessive engine oil consumption
    • Contaminated fuel

    After repair is completed, go to step  14.

  5. Using scan tool, store DTC information from PCM. Clear DTC information from PCM. Reset trim values. Start and idle engine. Ensure engine is at normal operating temperature. Operate vehicle within the conditions required for setting DTC P0133. If DTC reset and scan tool displays FAIL THIS IGNITION, go to step  7. If DTC did not reset and scan tool did not display FAIL THIS IGNITION, go to next step.
  6. DTC P0133 is intermittent. See DIAGNOSTIC AIDS . If any other DTCs are present, diagnose and repair DTCs as necessary.
  7. Inspect the following:
    • Exhaust leaks
    • Proper O2S 1 installation
    • O2S 1 connector and wiring for corrosion or damage
    • O2S 1 ground circuit

    If a problem is found, replace O2S 1 and go to step  14. If no problems are found, go to next step.

  8. Disconnect O2S 1 connector. Turn ignition on. Using scan tool, monitor O2S 1 voltage. If voltage is 351-551 mV, go to next step. If voltage is not 351-551 mV, go to step  11.
  9. Connect a jumper wire between ground and signal circuit (Purple wire) terminal at O2S 1 harness connector. If voltage is less than 20 mV, go to next step. If voltage is 20 mV or greater, go to step  12.
  10. Check for causes of sensor contamination. Possible causes are:
    • Use of silicon sealant
    • Engine coolant leaking into combustion chamber
    • Excessive engine oil consumption
    • Contaminated fuel

    After repair is completed, go to step  13.

  11. Repair short to ground in O2S 1 signal circuit (Purple wire). After repairs, go to step  14.
  12. Ensure ignition off. Disconnect PCM connectors. Check continuity of O2S 1 ground circuit (Tan wire) between ground and terminal No. 21 on PCM Black connector. Check continuity of O2S 1 signal circuit (Purple wire) between O2S 1 connector and terminal No. 22 on PCM Black connector. Resistance for both circuits should be less than 5 ohms. Repair as needed. After repairs, go to step  14.
  13. Replace O2S 1. Once repair is complete, go to next step.
  14. Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Reset fuel trim values. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function, then enter DTC P0133. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step  2.
  15. If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, no problem is indicated at this time.
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