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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 68 (Engine Control System Self-Diagnostics - 3.8L) >> Diagnostic Tests >> DTC P0141: Ho2S 2 Heater Performance - Sensor 2 (Regal) >> Diagnostic Procedures

Diagnostic Procedures

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  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing Diagnostic System Check - Engine Controls, go to next step.
    2. NOTE: If the engine has just been operating, allow the engine to cool for 1 hour before proceeding.
  2. Turn on the ignition, with the engine off. Observe the HO2S 2 voltage on the scan tool. Does HO2S voltage go from bias voltage to more than 600 millivolts, or to less than 300 millivolts within 2 minutes? If yes, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM. If no, go to next step.
  3. Inspect the fuse for the HO2S 2 ignition 1 voltage circuit. Is the fuse open? If yes, go to step  15. If no, go to next step.
    4. NOTE: Use a known-good ground. DO NOT use the HO2S 2 heater ground or the HO2S 2 low signal circuit.
  4. Raise the vehicle. Disconnect the HO2S 2 electrical connector. Probe the ignition 1 voltage circuit at the HO2S 2 electrical connector on the PCM harness side with a test lamp connected to ground. Does the test lamp illuminate? If yes, go to next step. If no, go to step  7.
  5. Connect the test lamp between HO2S 2 ignition 1 voltage and HO2S 2 heater ground. Does test lamp illuminate? If yes, go to next step. If no, go to step  8.
  6. Allow the HO2S to cool for at least 10 minutes. Using a DMM, measure the resistance between the Brown wires for the HO2S 2 ignition 1 voltage and the HO2S 2 heater ground at the HO2S 2 pigtail. Does the resistance measure 4-6 ohms? If yes, go to step  9. If no, go to step  14.
  7. Repair the open HO2S 2 ignition 1 voltage circuit to the HO2S 2. After repairs, go to step  16.
  8. Repair the open HO2S 2 heater ground circuit. After repairs, go to step  16.
  9. Inspect the HO2S 2 harness terminals for a poor connection. If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  10. Turn off the ignition. Disconnect the PCM and test the HO2S 2 high signal circuit and the HO2S 2 low signal circuit for continuity. If the HO2S 2 high signal circuit or if the HO2S low signal circuit measures more than 5 ohms, repair the circuit as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  11. Inspect the HO2S 2 high signal circuit and the HO2S 2 low signal circuit for a poor connection at the HO2S 2 harness connector. If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  12. Inspect the HO2S 2 low signal circuit for a poor connection at the PCM. If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  13. Inspect the HO2S 2 high signal circuit for a poor connection at the PCM. If a condition is found, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  14. Replace HO2S 2. After repairs, go to step  16.
  15. Repair the short to ground in the HO2S 1 or in the HO2S 2 ignition 1 voltage circuit, and replace the fuse. After repairs, go to next step.
  16. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within Conditions for Running DTC. Does DTC run and pass? If yes, go to next step. If no, go to step  2.
  17. Using scan tool, observe stored information. Does scan tool displays any DTCs that have not been diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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