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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 P0134: O2S Insufficient Activity 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 into scan tool. Clear DTCs from PCM. Reset fuel trim values. Start engine and run until normal operating temperature is reached. 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 P0134 is intermittent. Go to DIAGNOSTIC AIDS . If any other DTCs are present, diagnose DTCs as necessary.
  4. Inspect exhaust manifold for leaks. Repair as needed. After repair, go to step  10. If no exhaust leaks were present, go to next step.
  5. Disconnect O2S 1 connector. Connect a jumper wire between ground and sensor signal circuit (Purple wire) terminal at O2S 1 harness connector. Turn ignition on, with engine off. If voltage is less than 20 mV, go to step  6. If voltage is 20 mV or greater, go to next step.
  6. Turn ignition off. Disconnect jumper wire. Disconnect PCM Black harness connector. Using DVOM, measure resistance of Purple wire between O2S 1 harness connector terminal and terminal No. 22 on PCM harness 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  10.
  7. Turn ignition off. Inspect PCM Black harness connector for faulty terminals or poor connection. Repair faulty terminals or poor connection as necessary. After repairs, go to step  10. 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  10. If test light is not illuminated, go to next step.
  9. Ensure ignition is off. Connect O2S 1 connector. Using DVOM, measure resistance between ground and terminal No. 21 (Tan wire) on PCM Black harness connector. If resistance is less than 5 ohms, replace PCM. Program new PCM using appropriate equipment. See PROGRAMMING . After replacing PCM, go to next step. If resistance is 5 ohms or greater, repair open circuit and go to next step.
  10. 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 P0134. 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.
  11. 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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