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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 P1133: O2S Insufficient Switching 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. 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. Monitor O2S 1 voltage. If voltage is 300-600 mV, go to step  4. If voltage is not 300-600 mV, go to next step.
  3. DTC P1133 is intermittent. See DIAGNOSTIC AIDS . Check for other DTCs. If other DTCs are present, diagnose affected DTCs. If no other DTCs are present, go to next step.
  4. Check exhaust manifold for leaks. Repair as necessary. After repair is completed, go to step  11. If exhaust is okay, go to next step.
  5. Turn ignition off. Disconnect O2S 1 harness connector. Connect a jumper wire between ground and signal circuit (Purple wire) terminal at O2S 1 harness connector. Turn ignition on. If voltage is less than 20 mV, go to step  7. If voltage is 20 mV or greater, go to next step.
  6. Turn ignition off. Remove jumper wire. Disconnect PCM Black connector. Check continuity of O2S 1 signal circuit (Purple wire) between O2S 1 connector and terminal No. 22 on PCM Black connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open circuit and go to  11.
  7. Inspect PCM harness connector. Ensure connector is clean and tight. Repair as needed and go to  11. If connector is okay, go to next step.
  8. Remove jumper wire. Connect test light between battery voltage and terminal No. 21 (Tan wire) on PCM Black harness connector. If test light is illuminated, replace oxygen sensor. After replacing sensor, go to step  11. If test light is not illuminated, go to next step.
  9. Measure resistance between ground and terminal No. 21 (Tan wire) on PCM Black connector. If resistance is less than 5 ohms, go to step  10. If resistance is 5 ohms or greater, repair open in ground circuit. After repairs, go to step  10.
  10. Replace PCM. Program replacement PCM using appropriate equipment. See PROGRAMMING . After replacing PCM, go to next step.
  11. 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. Operate vehicle within conditions required for setting this DTC. Select SPECIFIC DTC function, then enter DTC P1133. If scan tool indicates TEST RAN AND PASSED, go to next step. If scan tool does not indicate TEST RAN AND PASSED, repeat step  3.
  12. If any other DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, go to DIAGNOSTIC AIDS .
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